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Home Lớp 7 Toán lớp 7 - Sách kết nối tri thức Đơn thức. Đơn thức đồng dạngBài tập trung bình

{"common":{"save":0,"post_id":"1398","level":2,"total":20,"point":5,"point_extra":0},"segment":[{"id":"1121","post_id":"1398","mon_id":"0","chapter_id":"0","question":"Ch\u1ecdn nh\u1eefng<\/u> \u0111\u00e1p \u00e1n \u0111\u00fang","options":{"time":24,"part":[{"title":"Ch\u1ecdn nh\u1eefng<\/u> \u0111\u00e1p \u00e1n \u0111\u00fang","title_trans":"Ch\u1ecdn \u0111\u01b0\u1ee3c nhi\u1ec1u \u0111\u00e1p \u00e1n","temp":"checkbox","correct":[["2","4"]],"list":[{"point":5,"img":"","ques":"Trong c\u00e1c bi\u1ec3u th\u1ee9c sau, nh\u1eefng bi\u1ec3u th\u1ee9c n\u00e0o l\u00e0 \u0111\u01a1n th\u1ee9c?","hint":"","column":2,"number_true":2,"select":["A. $-2+x^2y$","B. $-\\dfrac{1}{3}x^3y^2$","C. $\\dfrac{x+y^2}{2x}$","D. $-\\dfrac{3}{4}x^5y(-7x)$"],"explain":"Trong c\u00e1c bi\u1ec3u th\u1ee9c tr\u00ean, bi\u1ec3u th\u1ee9c $-\\dfrac{1}{3}x^3y^2$ v\u00e0 bi\u1ec3u th\u1ee9c $-\\dfrac{3}{4}x^5y(-7x)$ l\u00e0 c\u00e1c \u0111\u01a1n th\u1ee9c. <br\/> V\u1eady \u0111\u00e1p \u00e1n c\u1ea7n ch\u1ecdn l\u00e0 B v\u00e0 D.<\/span><\/span>"}]}]},"correct":"","level":"2","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:22:56"},{"id":"1122","post_id":"1398","mon_id":"0","chapter_id":"0","question":"Ch\u1ecdn nh\u1eefng<\/u> \u0111\u00e1p \u00e1n \u0111\u00fang","options":{"time":24,"part":[{"title":"Ch\u1ecdn nh\u1eefng<\/u> \u0111\u00e1p \u00e1n \u0111\u00fang","title_trans":"Ch\u1ecdn \u0111\u01b0\u1ee3c nhi\u1ec1u \u0111\u00e1p \u00e1n","temp":"checkbox","correct":[["1","3"]],"list":[{"point":5,"img":"","ques":"Trong c\u00e1c bi\u1ec3u th\u1ee9c sau, nh\u1eefng bi\u1ec3u th\u1ee9c n\u00e0o kh\u00f4ng ph\u1ea3i l\u00e0 \u0111\u01a1n th\u1ee9c?","hint":"","column":2,"number_true":2,"select":["A. $4a-3ab+c$","B. $ab^2$","C. $a^2+2b+c$","D. $3aca^2c^3$"],"explain":"Trong c\u00e1c bi\u1ec3u th\u1ee9c tr\u00ean, bi\u1ec3u th\u1ee9c $4a-3ab+c$ v\u00e0 bi\u1ec3u th\u1ee9c $a^2+2b+c$ kh\u00f4ng ph\u1ea3i l\u00e0 \u0111\u01a1n th\u1ee9c. <br\/> V\u1eady \u0111\u00e1p \u00e1n c\u1ea7n ch\u1ecdn l\u00e0 A v\u00e0 C.<\/span><\/span>"}]}]},"correct":"","level":"2","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:22:56"},{"id":"1123","post_id":"1398","mon_id":"0","chapter_id":"0","question":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","options":{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"ques":" \u0110\u01a1n th\u1ee9c n\u00e0o sau \u0111\u00e2y c\u00f3 b\u1eadc l\u00e0 $1?$ <\/span>","select":["A. $x$","B. $0$","C. $1$","D. $xy$"],"hint":"","explain":"H\u01b0\u1edbng d\u1eabn:<\/span><br\/>B\u1eadc c\u1ee7a \u0111\u01a1n th\u1ee9c c\u00f3 h\u1ec7 s\u1ed1 kh\u00e1c $0$ l\u00e0 t\u1ed5ng s\u1ed1 m\u0169 c\u1ee7a t\u1ea5t c\u1ea3 c\u00e1c bi\u1ebfn c\u00f3 trong \u0111\u01a1n th\u1ee9c \u0111\u00f3. <br\/>B\u00e0i gi\u1ea3i:<\/span><br\/>\u0110\u01a1n th\u1ee9c $x$ c\u00f3 b\u1eadc l\u00e0 $1$ <br\/> \u0110\u01a1n th\u1ee9c $0$ kh\u00f4ng c\u00f3 b\u1eadc <br\/> \u0110\u01a1n th\u1ee9c $1$ c\u00f3 b\u1eadc l\u00e0 $0$ <br\/> \u0110\u01a1n th\u1ee9c $xy$ c\u00f3 b\u1eadc l\u00e0 $2$ <br\/> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 A.<\/span><\/span>","column":4}]}]},"correct":"","level":"2","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:22:56"},{"id":"1124","post_id":"1398","mon_id":"0","chapter_id":"0","question":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","options":{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[4]],"list":[{"point":5,"ques":" \u0110\u01a1n th\u1ee9c $28xy^2.(-2xy^2z)$ c\u00f3 ph\u1ea7n bi\u1ebfn l\u00e0: <\/span>","select":["A. $xy^2$","B. $xy^2z$","C. $x^2y^2z$","D. $x^2y^4z$"],"hint":"","explain":"H\u01b0\u1edbng d\u1eabn:<\/span><br\/>R\u00fat g\u1ecdn \u0111\u01a1n th\u1ee9c \u0111\u00e3 cho r\u1ed3i t\u00ecm ph\u1ea7n bi\u1ebfn c\u1ee7a n\u00f3. <br\/>B\u00e0i gi\u1ea3i:<\/span><br\/>Ta c\u00f3: <br\/>$28xy^2.(-2xy^2z)=[28.(-2)](xx)(y^2y^2)z=-56x^2y^4z$ <br\/> Ph\u1ea7n bi\u1ebfn c\u1ee7a $-56x^2y^4z$ l\u00e0 $x^2y^4z$ <br\/> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 D.<\/span><\/span>","column":4}]}]},"correct":"","level":"2","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:22:56"},{"id":"1125","post_id":"1398","mon_id":"0","chapter_id":"0","question":"L\u1ef1a ch\u1ecdn \u0111\u00fang hay sai","options":{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00fang hay sai","title_trans":"","temp":"true_false","correct":[["t","f","f"]],"list":[{"point":5,"image":"","col_name":["Cho \u0111\u01a1n th\u1ee9c $-2,5ax^3$ v\u1edbi $a$ l\u00e0 h\u1eb1ng s\u1ed1, $x$ l\u00e0 bi\u1ebfn th\u00ec:","\u0110\u00fang","Sai"],"arr_ques":[" H\u1ec7 s\u1ed1 c\u1ee7a \u0111\u01a1n th\u1ee9c l\u00e0 $-2,5a$ "," Ph\u1ea7n bi\u1ebfn c\u1ee7a \u0111\u01a1n th\u1ee9c l\u00e0 $ax^3$","B\u1eadc c\u1ee7a \u0111\u01a1n th\u1ee9c l\u00e0 $4$"],"hint":"","explain":[" \u0110\u00fang"," <br\/> Sai, v\u00ec: Ph\u1ea7n bi\u1ebfn c\u1ee7a \u0111\u01a1n th\u1ee9c $-2,5ax^3$ l\u00e0 $x^3$ ","<br\/> Sai, v\u00ec: B\u1eadc c\u1ee7a \u0111\u01a1n th\u1ee9c $-2,5ax^3$ l\u00e0 $3$"]}]}]},"correct":"","level":"2","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:22:56"},{"id":"1126","post_id":"1398","mon_id":"0","chapter_id":"0","question":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 \u0111\u00fang nh\u1ea5t v\u00e0o \u00f4 tr\u1ed1ng","options":{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 \u0111\u00fang nh\u1ea5t v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["36"]]],"list":[{"point":5,"width":40,"content":"","type_input":"","ques":" Gi\u00e1 tr\u1ecb c\u1ee7a \u0111\u01a1n th\u1ee9c $-\\dfrac{2}{3}x^3y^2z$ t\u1ea1i $x=-3;y=-2;z=\\dfrac{1}{2}$ l\u00e0 _input_ ","hint":"Thay gi\u00e1 tr\u1ecb c\u1ee7a $x;y;z$ v\u00e0o \u0111\u01a1n th\u1ee9c r\u1ed3i t\u00ednh.","explain":" Thay $x=-3;y=-2;z=\\dfrac{1}{2}$ v\u00e0o \u0111\u01a1n th\u1ee9c $-\\dfrac{2}{3}x^3y^2z$ ta \u0111\u01b0\u1ee3c: <br\/> $-\\dfrac{2}{3}x^3y^2z=-\\dfrac{2}{3}.(-3)^3.(-2)^2.\\dfrac{1}{2}=-\\dfrac{2}{3}.(-27).4.\\dfrac{1}{2}=36 $ <br\/> V\u1eady s\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $36.$<\/span><\/span>"}]}]},"correct":"","level":"2","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:22:56"},{"id":"1127","post_id":"1398","mon_id":"0","chapter_id":"0","question":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 \u0111\u00fang nh\u1ea5t v\u00e0o \u00f4 tr\u1ed1ng","options":{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 \u0111\u00fang nh\u1ea5t v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank_random","correct":[[["2"],["-2"]]],"list":[{"point":5,"width":40,"content":"","type_input":"","ques":" T\u1ea1i gi\u00e1 tr\u1ecb n\u00e0o c\u1ee7a $x$ th\u00ec \u0111\u01a1n th\u1ee9c $\\dfrac{3}{4}x^2y^3$ c\u00f3 gi\u00e1 tr\u1ecb l\u00e0 $\\dfrac{1}{9}$ bi\u1ebft r\u1eb1ng $y=\\dfrac{1}{3}$ <br\/> \u0110\u00e1p \u00e1n: <\/b> $\\left[ \\begin{align} & x= \\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{} \\\\ & x=\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{} \\\\ \\end{align} \\right.$ <\/span> ","hint":"Thay gi\u00e1 tr\u1ecb c\u1ee7a $y$ v\u00e0o \u0111\u01a1n th\u1ee9c, cho \u0111\u01a1n th\u1ee9c b\u1eb1ng $\\dfrac{1}{9}$ r\u1ed3i t\u00ecm $x$ ","explain":" Thay $y=\\dfrac{1}{3}$ v\u00e0o \u0111\u01a1n th\u1ee9c $\\dfrac{3}{4}x^2y^3$ ta \u0111\u01b0\u1ee3c: <br\/> $\\dfrac{3}{4}x^2y^3=\\dfrac{3}{4}{{x}^{2}}.{{\\left( \\dfrac{1}{3} \\right)}^{3}}=\\dfrac{1}{36}{{x}^{2}}$ <br\/> Do gi\u00e1 tr\u1ecb c\u1ee7a \u0111\u01a1n th\u1ee9c $\\dfrac{3}{4}x^2y^3$ l\u00e0 $\\dfrac{1}{9}$ khi $y=\\dfrac{1}{3}$ n\u00ean ta c\u00f3: <br\/> $\\begin{align} & \\dfrac{1}{36}{{x}^{2}}=\\dfrac{1}{9} \\\\ & \\Rightarrow {{x}^{2}}=\\dfrac{1}{9}:\\dfrac{1}{36} \\\\ & \\Rightarrow {{x}^{2}}=\\dfrac{1}{9}\\cdot \\dfrac{36}{1} \\\\ & \\Rightarrow {{x}^{2}}=4 \\\\ & \\Rightarrow x=\\pm 2 \\\\ \\end{align}$ <br\/> V\u1eady c\u00e1c s\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o c\u00e1c \u00f4 tr\u1ed1ng l\u00e0 $2$ v\u00e0 $-2$<\/span><\/span>"}]}]},"correct":"","level":"2","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:22:56"},{"id":"1128","post_id":"1398","mon_id":"0","chapter_id":"0","question":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 \u0111\u00fang nh\u1ea5t v\u00e0o \u00f4 tr\u1ed1ng","options":{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 \u0111\u00fang nh\u1ea5t v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["10"]]],"list":[{"point":5,"width":40,"content":"","type_input":"","ques":" B\u1eadc c\u1ee7a \u0111\u01a1n th\u1ee9c $3a{{k}^{2}}\\left( -2k{{x}^{3}} \\right){{k}^{3}}$ l\u00e0 _input_ ","hint":"Thu g\u1ecdn \u0111\u01a1n th\u1ee9c \u0111\u00e3 cho r\u1ed3i t\u00ecm b\u1eadc c\u1ee7a n\u00f3.","explain":" Ta thu g\u1ecdn \u0111\u01a1n th\u1ee9c: <br\/> $3a{{k}^{2}}\\left( -2k{{x}^{3}} \\right){{k}^{3}}=\\left[ 3.\\left( -2 \\right) \\right]a\\left( {{k}^{2}}k{{k}^{3}} \\right){{x}^{3}}=-6a{{k}^{6}}{{x}^{3}}$ <br\/> $\\Rightarrow$ B\u1eadc c\u1ee7a \u0111\u01a1n th\u1ee9c $-6a{{k}^{6}}{{x}^{3}}$ l\u00e0 $10$ <br\/> V\u1eady s\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $10.$<\/span><\/span>"}]}]},"correct":"","level":"2","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:22:56"},{"id":"1129","post_id":"1398","mon_id":"0","chapter_id":"0","question":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","options":{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"ques":" Cho \u0111\u01a1n th\u1ee9c $A=ab^2c^2a$. T\u00ednh $A^3.$ <\/span>","select":["A. $A^3=(abc)^6$","B. $A^3=(abc)^5$","C. $A^3=a^3b^6c^6$","D. $A^3=a^3b^5c^5$ "],"hint":"Thu g\u1ecdn \u0111\u01a1n th\u1ee9c $A$ r\u1ed3i t\u00ednh $A^3$","explain":" Ta c\u00f3: $A=ab^2c^2a=a^2b^2c^2=(abc)^2$ <br\/> Do \u0111\u00f3: $A^3=[(abc)^2]^3=(abc)^6$ <br\/> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 A.<\/span><\/span>","column":2}]}]},"correct":"","level":"2","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:22:56"},{"id":"1130","post_id":"1398","mon_id":"0","chapter_id":"0","question":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","options":{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[3]],"list":[{"point":5,"ques":" Thu g\u1ecdn \u0111\u01a1n th\u1ee9c $ \\left( -\\dfrac{2}{3}{{a}^{2}}b \\right){{b}^{2}}a.\\dfrac{9}{4}{{\\left( {{a}^{2}}{{b}^{2}} \\right)}^{3}}$ \u0111\u01b0\u1ee3c k\u1ebft qu\u1ea3 l\u00e0: <\/span>","select":["A. $-2a^6b^8$","B. $-3a^8b^6$","C. $-\\dfrac{3}{2}{{a}^{9}}{{b}^{9}}$","D. $-\\dfrac{2}{3}{{a}^{9}}{{b}^{9}}$ "],"hint":"","explain":" Ta c\u00f3: <br\/> $\\begin{align} & \\left( -\\dfrac{2}{3}{{a}^{2}}b \\right){{b}^{2}}a.\\dfrac{9}{4}{{\\left( {{a}^{2}}{{b}^{2}} \\right)}^{3}} \\\\ & =\\left( -\\dfrac{2}{3}{{a}^{2}}b \\right){{b}^{2}}a.\\dfrac{9}{4}{{a}^{6}}{{b}^{6}} \\\\ & =\\left[ \\left( -\\dfrac{2}{3} \\right).\\dfrac{9}{4} \\right]\\left( {{a}^{2}}a{{a}^{6}}\\, \\right)\\left( b{{b}^{2}}{{b}^{6}} \\right) \\\\ & =-\\dfrac{3}{2}{{a}^{9}}{{b}^{9}} \\\\ \\end{align}$ <br\/> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 C.<\/span><\/span>","column":2}]}]},"correct":"","level":"2","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:22:56"},{"id":"1131","post_id":"1398","mon_id":"0","chapter_id":"0","question":"Kh\u1eb3ng \u0111\u1ecbnh sau \u0111\u00e2y \u0110\u00fang hay Sai","options":{"time":24,"part":[{"title":"Kh\u1eb3ng \u0111\u1ecbnh sau \u0111\u00e2y \u0110\u00fang hay Sai","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"ques":" B\u1eadc c\u1ee7a c\u00e1c \u0111\u01a1n th\u1ee9c \u0111\u1ed3ng d\u1ea1ng l\u00e0 b\u1eb1ng nhau. <\/span>","select":["\u0110\u00fang","Sai "],"hint":"","explain":" C\u00e1c \u0111\u01a1n th\u1ee9c \u0111\u1ed3ng d\u1ea1ng c\u00f3 b\u1eadc b\u1eb1ng nhau v\u00ec ch\u00fang c\u00f3 c\u00f9ng ph\u1ea7n bi\u1ebfn. <br\/> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 \u0110\u00fang.<\/span><\/span>","column":2}]}]},"correct":"","level":"2","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:22:56"},{"id":"1132","post_id":"1398","mon_id":"0","chapter_id":"0","question":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","options":{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[2]],"list":[{"point":5,"ques":" X\u00e1c \u0111\u1ecbnh h\u1eb1ng s\u1ed1 $k$ \u0111\u1ec3 hi\u1ec7u hai \u0111\u01a1n th\u1ee9c sau \u0111\u00e2y lu\u00f4n c\u00f3 gi\u00e1 tr\u1ecb kh\u00f4ng d\u01b0\u01a1ng v\u1edbi m\u1ecdi gi\u00e1 tr\u1ecb c\u1ee7a bi\u1ebfn: $kx^2y^4z^2-x^2y^4z^2$ <\/span>","select":["A. $k \\ge 1$","B. $k\\le 1$","C. $k > 0$","D. $k < 0$ "],"hint":"T\u00ednh hi\u1ec7u hai \u0111\u01a1n th\u1ee9c \u0111\u00e3 cho. \u0110\u00e1nh gi\u00e1 \u0111\u1ec3 t\u00ecm \u0111i\u1ec1u ki\u1ec7n c\u1ee7a $k$","explain":" Ta c\u00f3: <br\/> $kx^2y^4z^2-x^2y^4z^2=(k-1)x^2y^4z^2$ <br\/> Do $x^2y^4z^2 \\ge 0$ v\u1edbi m\u1ecdi $x;y;z$ n\u00ean \u0111\u1ec3 $(k-1)x^2y^4z^2 \\le 0$ ta ph\u1ea3i c\u00f3 $k-1 \\le 0$ hay $k\\le 1$ <br\/> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 B.<\/span><\/span>","column":4}]}]},"correct":"","level":"2","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:22:56"},{"id":"1133","post_id":"1398","mon_id":"0","chapter_id":"0","question":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 \u0111\u00fang nh\u1ea5t v\u00e0o \u00f4 tr\u1ed1ng","options":{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 \u0111\u00fang nh\u1ea5t v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["1"]]],"list":[{"point":5,"width":40,"content":"","type_input":"","ques":" X\u00e1c \u0111\u1ecbnh h\u1eb1ng s\u1ed1 $a$ \u0111\u1ec3 t\u1ed5ng c\u00e1c \u0111\u01a1n th\u1ee9c sau \u0111\u00e2y b\u1eb1ng $5xy^3$ <br\/> $axy^3;\\,-3axy^3;\\,7xy^3$ <br\/> \u0110\u00e1p \u00e1n: <\/b> $a=\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}$<\/span>","hint":"T\u00ednh t\u1ed5ng c\u00e1c \u0111\u01a1n th\u1ee9c \u0111\u1ed3ng d\u1ea1ng \u0111\u00e3 cho. Cho t\u1ed5ng \u0111\u00f3 b\u1eb1ng $5xy^3$ r\u1ed3i t\u00ecm $a$","explain":" Ta c\u00f3: <br\/> $axy^3+(-3axy^3)+7xy^3=(a-3a+7)xy^3=(7-2a)xy^3$ <br\/> \u0110\u1ec3 t\u1ed5ng tr\u00ean b\u1eb1ng $5xy^3$ th\u00ec: <br\/> $7-2a=5 \\Rightarrow 2a=2 \\Rightarrow a=1$ <br\/> V\u1eady s\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $1.$<\/span><\/span>"}]}]},"correct":"","level":"2","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:22:56"},{"id":"1134","post_id":"1398","mon_id":"0","chapter_id":"0","question":"Kh\u1eb3ng \u0111\u1ecbnh sau \u0110\u00fang hay Sai","options":{"time":24,"part":[{"title":"Kh\u1eb3ng \u0111\u1ecbnh sau \u0110\u00fang hay Sai","title_trans":"","temp":"multiple_choice","correct":[[2]],"list":[{"point":5,"ques":" \u0110\u01a1n th\u1ee9c $2{{x}^{2}}y.{{\\left( -\\dfrac{1}{2}xy \\right)}^{2}}.4x{{y}^{2}}$ c\u00f3 b\u1eadc l\u00e0 $8.$ <\/span>","select":["\u0110\u00fang","Sai "],"hint":"Thu g\u1ecdn \u0111\u01a1n th\u1ee9c \u0111\u00e3 cho r\u1ed3i t\u00ecm b\u1eadc c\u1ee7a n\u00f3.","explain":" Ta c\u00f3: <br\/> $\\begin{align} & 2{{x}^{2}}y.{{\\left( -\\dfrac{1}{2}xy \\right)}^{2}}.4x{{y}^{2}} \\\\ & =2{{x}^{2}}y.\\dfrac{1}{4}{{x}^{2}}{{y}^{2}}.4x{{y}^{2}} \\\\ & =\\left( 2.\\dfrac{1}{4}.4 \\right)\\left( {{x}^{2}}{{x}^{2}}x \\right)\\left( y{{y}^{2}}{{y}^{2}} \\right) \\\\ & =2{{x}^{5}}{{y}^{5}} \\\\ \\end{align}$ <br\/> \u0110\u01a1n th\u1ee9c $2{{x}^{5}}{{y}^{5}}$ c\u00f3 b\u1eadc l\u00e0 $10$ <br\/> $\\Rightarrow$ Kh\u1eb3ng \u0111\u1ecbnh c\u1ee7a \u0111\u1ec1 b\u00e0i l\u00e0 sai. <br\/> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 Sai.<\/span><\/span>","column":2}]}]},"correct":"","level":"2","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:22:56"},{"id":"1135","post_id":"1398","mon_id":"0","chapter_id":"0","question":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","options":{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"ques":" Ph\u1ea7n bi\u1ebfn c\u1ee7a \u0111\u01a1n th\u1ee9c $(-2x^2yz^3).(-x^3y^2z)^3$ l\u00e0:<\/span>","select":["A. $x^{11}y^7z^6$","B. $x^8y^6z^6$","C. $x^{11}y^6z^3$","D. $x^8y^7z^3$ "],"hint":"","explain":"H\u01b0\u1edbng d\u1eabn:<\/span><br\/>Thu g\u1ecdn \u0111\u01a1n th\u1ee9c \u0111\u00e3 cho r\u1ed3i t\u00ecm ph\u1ea7n bi\u1ebfn c\u1ee7a n\u00f3. <br\/> B\u00e0i gi\u1ea3i:<\/span><br\/> Ta c\u00f3: <br\/>$(-2x^2yz^3).(-x^3y^2z)^3$ <br\/> $=(-2x^2yz^3).(-x^9y^6z^3)$ <br\/> $=[(-2).(-1)](x^2x^9)(yy^6)(z^3z^3)$ <br\/> $=2x^{11}y^7z^6$ <br\/> Ph\u1ea7n bi\u1ebfn c\u1ee7a \u0111\u01a1n th\u1ee9c \u0111\u00e3 cho l\u00e0 $x^{11}y^7z^6$ <br\/> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 A.<\/span><\/span>","column":4}]}]},"correct":"","level":"2","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:22:56"},{"id":"1136","post_id":"1398","mon_id":"0","chapter_id":"0","question":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","options":{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[4]],"list":[{"point":5,"ques":" Cho t\u1ed5ng sau: $x^3+5x^3+(-3x^3)$ <br\/> V\u1edbi $x=-2$ th\u00ec t\u1ed5ng tr\u00ean c\u00f3 gi\u00e1 tr\u1ecb l\u00e0:<\/span>","select":["A. $-16$","B. $-18$","C. $-72$","D. $-24$ "],"hint":"","explain":"H\u01b0\u1edbng d\u1eabn:<\/span><br\/> T\u00ednh t\u1ed5ng c\u00e1c \u0111\u01a1n th\u1ee9c \u0111\u1ed3ng d\u1ea1ng \u0111\u00e3 cho. <br\/> Thay $x=-2$ v\u00e0o k\u1ebft qu\u1ea3 c\u1ee7a t\u1ed5ng v\u1eeba t\u00ecm \u0111\u01b0\u1ee3c. <br\/> B\u00e0i gi\u1ea3i:<\/span><br\/> Ta c\u00f3: <br\/>$x^3+5x^3+(-3x^3)=(1+5-3)x^3=3x^3$ <br\/> Thay $x=-2$ v\u00e0o k\u1ebft qu\u1ea3 tr\u00ean ta \u0111\u01b0\u1ee3c: <br\/> $3.(-2)^3 =3.(-8)=-24$ <br\/> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 D.<\/span><\/span>","column":4}]}]},"correct":"","level":"2","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:22:56"},{"id":"1137","post_id":"1398","mon_id":"0","chapter_id":"0","question":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 \u0111\u00fang nh\u1ea5t v\u00e0o \u00f4 tr\u1ed1ng","options":{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 \u0111\u00fang nh\u1ea5t v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["-1"]]],"list":[{"point":5,"width":40,"content":"","type_input":"","ques":" T\u00ecm gi\u00e1 tr\u1ecb c\u1ee7a $x$ \u0111\u1ec3 t\u1ed5ng $-4x^5+7x^5+(-23x^5)$ c\u00f3 gi\u00e1 tr\u1ecb b\u1eb1ng $20.$ <br\/> \u0110\u00e1p \u00e1n: <\/b> $x=\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}$<\/span>","hint":"T\u00ednh t\u1ed5ng c\u00e1c \u0111\u01a1n th\u1ee9c \u0111\u00e3 cho. Cho t\u1ed5ng \u0111\u00f3 b\u1eb1ng $20$ r\u1ed3i t\u00ecm $x$","explain":" Ta c\u00f3: <br\/> $-4x^5+7x^5+(-23x^5)=[(-4)+7+(-23)]x^5=-20x^5$ <br\/> \u0110\u1ec3 t\u1ed5ng tr\u00ean c\u00f3 gi\u00e1 tr\u1ecb b\u1eb1ng $20$ th\u00ec: <br\/> $-20x^5=20$ <br\/> $\\Rightarrow x^5=20:(-20)$ <br\/> $\\Rightarrow x^5=-1$ <br\/> $\\Rightarrow x=-1$ <br\/> V\u1eady s\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $-1.$<\/span><\/span>"}]}]},"correct":"","level":"2","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:22:56"},{"id":"1138","post_id":"1398","mon_id":"0","chapter_id":"0","question":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","options":{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[2]],"list":[{"point":5,"ques":" X\u00e1c \u0111\u1ecbnh \u0111\u01a1n th\u1ee9c $M$ \u0111\u1ec3 $2x^4y^3+M=-3x^4y^3$<\/span>","select":["A. $M=-x^4y^3$","B. $M=-5x^4y^3$","C. $M=5x^4y^3$","D. $M=x^4y^3$ "],"hint":"","explain":"H\u01b0\u1edbng d\u1eabn:<\/span><br\/> Mu\u1ed1n t\u00ecm \u0111\u01a1n th\u1ee9c ch\u01b0a bi\u1ebft trong m\u1ed9t t\u1ed5ng ta l\u1ea5y t\u1ed5ng tr\u1eeb \u0111i \u0111\u01a1n th\u1ee9c \u0111\u00e3 bi\u1ebft. <br\/> B\u00e0i gi\u1ea3i:<\/span><br\/> Ta c\u00f3: <br\/>$2x^4y^3+M=-3x^4y^3$ <br\/> $\\Rightarrow M=-3x^4y^3-2x^4y^3$ <br\/> $\\Rightarrow M=(-3-2)x^4y^3$ <br\/> $\\Rightarrow M=-5x^4y^3$ <br\/> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 B.<\/span><\/span>","column":2}]}]},"correct":"","level":"2","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:22:56"},{"id":"1139","post_id":"1398","mon_id":"0","chapter_id":"0","question":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","options":{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[2]],"list":[{"point":5,"ques":" T\u00ednh gi\u00e1 tr\u1ecb c\u1ee7a bi\u1ec3u th\u1ee9c $A=\\dfrac{1}{2}x{{y}^{2}}+\\dfrac{1}{3}x{{y}^{2}}+\\dfrac{1}{6}x{{y}^{2}}$ t\u1ea1i $x=2;y=-1$<\/span>","select":["A. $A=1$","B. $A=2$","C. $A=\\dfrac{5}{3}$","D. $A=-\\dfrac{4}{3}$ "],"hint":"","explain":"H\u01b0\u1edbng d\u1eabn:<\/span><br\/> Thu g\u1ecdn bi\u1ec3u th\u1ee9c: T\u1ed5ng c\u00e1c \u0111\u01a1n th\u1ee9c \u0111\u1ed3ng d\u1ea1ng <br\/> Thay gi\u00e1 tr\u1ecb $x;y$ v\u00e0o bi\u1ec3u th\u1ee9c thu g\u1ecdn r\u1ed3i t\u00ednh.<br\/> B\u00e0i gi\u1ea3i:<\/span><br\/> Ta c\u00f3: <br\/>$\\begin{align} & A=\\dfrac{1}{2}x{{y}^{2}}+\\dfrac{1}{3}x{{y}^{2}}+\\dfrac{1}{6}x{{y}^{2}} \\\\ & \\,\\,\\,\\,\\,=\\left( \\dfrac{1}{2}+\\dfrac{1}{3}+\\dfrac{1}{6} \\right)x{{y}^{2}} \\\\ & \\,\\,\\,\\,\\,=\\left( \\dfrac{3+2+1}{6} \\right)x{{y}^{2}} \\\\ & \\,\\,\\,\\,\\,\\,=x{{y}^{2}} \\\\ \\end{align}$ <br\/> Thay $x=2;y=-1$ v\u00e0o bi\u1ec3u th\u1ee9c \u0111\u00e3 thu g\u1ecdn ta c\u00f3: <br\/> $A=2.(-1)^2=2$ <br\/> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 B.<\/span><\/span>","column":2}]}]},"correct":"","level":"2","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:22:56"},{"id":"1140","post_id":"1398","mon_id":"0","chapter_id":"0","question":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 \u0111\u00fang nh\u1ea5t v\u00e0o \u00f4 tr\u1ed1ng","options":{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 \u0111\u00fang nh\u1ea5t v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["11"]]],"list":[{"point":5,"width":40,"content":"","type_input":"","ques":" T\u00ecm $m\\in \\mathbb{N}$, bi\u1ebft $5x^2y^3+mx^2y^3-6x^2y^3=10x^2y^3$ <br\/> \u0110\u00e1p \u00e1n: <\/b> $m=\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}$<\/span>","hint":"T\u00ednh t\u1ed5ng c\u00e1c \u0111\u01a1n th\u1ee9c \u1edf v\u1ebf tr\u00e1i. \u0110\u1ed3ng nh\u1ea5t h\u1ec7 s\u1ed1 \u1edf hai v\u1ebf c\u1ee7a \u0111\u1eb3ng th\u1ee9c \u0111\u1ec3 t\u00ecm $m$","explain":" Ta c\u00f3: <br\/> $5x^2y^3+mx^2y^3-6x^2y^3=10x^2y^3$ <br\/> $(5+m-6)x^2y^3=10x^2y^3$ <br\/> $(m-1)x^2y^3=10x^2y^3$ <br\/> $\\Rightarrow m-1=10$ <br\/> $\\Rightarrow m=11$ <br\/> V\u1eady s\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $11.$<\/span><\/span>"}]}]},"correct":"","level":"2","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:22:56"}]}