{"segment":[{"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":"Bi\u1ec3u th\u1ee9c $(x-y)^3.125$ c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c vi\u1ebft l\u1ea1i th\u00e0nh:","select":["A. $(5x-5y)^3$","B. $(25x-25y)^3$","C. $(x-5y)^3$","D. $(5x-y)^3$"],"hint":" Do $125=5^3$, ta vi\u1ebft bi\u1ec3u th\u1ee9c th\u00e0nh l\u1eadp ph\u01b0\u01a1ng c\u1ee7a m\u1ed9t hi\u1ec7u.","explain":"<span class='basic_left'> Ta c\u00f3: <br\/> $(x-y)^3.125=(x-y)^3.5^3$$=[(x-y).5]^3=(5x-5y)^3$. <br\/><span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 A.<\/span>","column":2}]}],"id_ques":431},{"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":"Bi\u1ec3u th\u1ee9c $27(a+b)^3$ c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c vi\u1ebft l\u1ea1i th\u00e0nh:","select":["A. $(27a+27b)^3$","B. $(3a+3b)^3$","C. $(3a+b)^3$","D. $(9a+9b)^3$"],"hint":" Do $27=3^3$, ta vi\u1ebft bi\u1ec3u th\u1ee9c th\u00e0nh l\u1eadp ph\u01b0\u01a1ng c\u1ee7a m\u1ed9t t\u1ed5ng.","explain":"<span class='basic_left'>Ta c\u00f3: <br\/> $27(a+b)^3=3^3(a+b)^3 =[3(a+b)]^3=(3a+3b)^3$. <br\/><span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span>","column":2}]}],"id_ques":432},{"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":"Vi\u1ebft l\u1ea1i bi\u1ec3u th\u1ee9c sau th\u00e0nh d\u1ea1ng l\u1eadp ph\u01b0\u01a1ng c\u1ee7a m\u1ed9t t\u1ed5ng ho\u1eb7c m\u1ed9t hi\u1ec7u:<br\/> $x^3-3x^2y+3xy^2-y^3$","select":["A. $(3x-y)^3$","B. $(x-y)^3$","C. $(x+y)^3$","D. $(1-xy)^3$"],"explain":"<span class='basic_left'> $x^3-3x^2y+3xy^2-y^3=(x-y)^3$. <br\/><span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span>","column":2}]}],"id_ques":433},{"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":"Vi\u1ebft l\u1ea1i bi\u1ec3u th\u1ee9c sau th\u00e0nh d\u1ea1ng l\u1eadp ph\u01b0\u01a1ng c\u1ee7a m\u1ed9t t\u1ed5ng ho\u1eb7c m\u1ed9t hi\u1ec7u:<br\/> $\\dfrac{1}{8}-\\dfrac{3}{4}x+\\dfrac{3}{2}{{x}^{2}}-{{x}^{3}}$","select":["A. $\\left(x-\\dfrac{1}{2}\\right)^3$","B. $(1-2x)^3$","C. $\\left(1-\\dfrac{1}{2}x \\right)^3$","D. $\\left(\\dfrac{1}{2}-x \\right)^3$"],"explain":"<span class='basic_left'> $\\dfrac{1}{8}-\\dfrac{3}{4}x+\\dfrac{3}{2}{{x}^{2}}-{{x}^{3}}$$={{\\left( \\dfrac{1}{2} \\right)}^{3}}-3.{{\\left( \\dfrac{1}{2} \\right)}^{2}}.x+3.\\dfrac{1}{2}.{{x}^{2}}-{{x}^{3}}$$={{\\left( \\dfrac{1}{2}-x \\right)}^{3}}$ . <br\/><span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 D.<\/span>","column":2}]}],"id_ques":434},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[3]],"list":[{"point":5,"ques":"Vi\u1ebft l\u1ea1i bi\u1ec3u th\u1ee9c sau th\u00e0nh d\u1ea1ng l\u1eadp ph\u01b0\u01a1ng c\u1ee7a m\u1ed9t t\u1ed5ng ho\u1eb7c m\u1ed9t hi\u1ec7u:<br\/> $8x^3-12x^2+6x-1$","select":["A. $(2x+1)^3$","B. $(1-2x)^3$","C. $(2x-1)^3$","D. $(8x-1)^3$"],"explain":"<span class='basic_left'> $8{{x}^{3}}-12{{x}^{2}}+6x-1$$={{\\left( 2x \\right)}^{3}}-3.{{\\left( 2x \\right)}^{2}}.1+3.2x.1-{{1}^{3}}$$={{\\left( 2x-1 \\right)}^{3}}$. <br\/><span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span>","column":2}]}],"id_ques":435},{"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":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai4/lv1/img\/3.jpg' \/><\/center>Gi\u00e1 tr\u1ecb c\u1ee7a bi\u1ec3u th\u1ee9c $A={{\\left( 2-5x \\right)}^{3}}-125{{x}^{3}}+10{{x}^{2}}-7x$ kh\u00f4ng ph\u1ee5 thu\u1ed9c v\u00e0o $x$. \u0110\u00fang hay sai?","select":["\u0110\u00fang","Sai"],"hint":"R\u00fat g\u1ecdn bi\u1ec3u th\u1ee9c, x\u00e9t k\u1ebft qu\u1ea3 thu \u0111\u01b0\u1ee3c c\u00f3 ch\u1ee9a $x$ hay kh\u00f4ng.<br\/> N\u1ebfu kh\u00f4ng ch\u1ee9a $x$ th\u00ec gi\u00e1 tr\u1ecb bi\u1ec3u th\u1ee9c kh\u00f4ng ph\u1ee5 thu\u1ed9c v\u00e0o $x$. ","explain":"<span class='basic_left'>Ta c\u00f3: <br\/>$ A={{\\left( 2-5x \\right)}^{3}}-125{{x}^{3}}+10{{x}^{2}}-7x $<br\/>$ =8-{{3.2}^{2}}.5x+3.2.{{\\left( 5x \\right)}^{2}}-{{\\left( 5x \\right)}^{3}}-125{{x}^{3}}+10{{x}^{2}}-7x $ <br\/> $ =8-60x+150{{x}^{2}}-125{{x}^{3}}-125{{x}^{3}}+10{{x}^{2}}-7x $<br\/>$ =-250{{x}^{3}}+160{{x}^{2}}-67x+8 $ . <br\/>V\u1eady gi\u00e1 tr\u1ecb c\u1ee7a $A$ ph\u1ee5 thu\u1ed9c v\u00e0o bi\u1ebfn $x$.<br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 Sai.<\/span>","column":2}]}],"id_ques":436},{"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":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai4/lv1/img\/2.jpg' \/><\/center>Gi\u00e1 tr\u1ecb c\u1ee7a bi\u1ec3u th\u1ee9c $A=(x-1)^3-x^3+3x^2-3x-1$ kh\u00f4ng ph\u1ee5 thu\u1ed9c v\u00e0o $x$. \u0110\u00fang hay sai? ","select":["\u0110\u00fang","Sai"],"hint":"R\u00fat g\u1ecdn bi\u1ec3u th\u1ee9c $A$, x\u00e9t k\u1ebft qu\u1ea3 thu \u0111\u01b0\u1ee3c c\u00f3 ch\u1ee9a $x$ hay kh\u00f4ng.<br\/> N\u1ebfu kh\u00f4ng ch\u1ee9a $x$ th\u00ec gi\u00e1 tr\u1ecb bi\u1ec3u th\u1ee9c kh\u00f4ng ph\u1ee5 thu\u1ed9c v\u00e0o $x$. ","explain":"<span class='basic_left'>Ta c\u00f3: <br\/>$ A={{(x-1)}^{3}}-{{x}^{3}}+3{{x}^{2}}-3x-1 $<br\/>$ ={{x}^{3}}-3{{x}^{2}}+3x-1-{{x}^{3}}+3{{x}^{2}}-3x-1 $<br\/>$ =-2 $. <br\/>V\u1eady gi\u00e1 tr\u1ecb c\u1ee7a $A$ kh\u00f4ng ph\u1ee5 thu\u1ed9c v\u00e0o bi\u1ebfn $x$.<br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 \u0110\u00fang<\/span>","column":2}]}],"id_ques":437},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 v\u00e0o \u00f4 tr\u1ed1ng ","title_trans":"","temp":"fill_the_blank","correct":[[["2"]]],"list":[{"point":5,"width":40,"type_input":"","ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai4/lv1/img\/4.jpg' \/><\/center>Bi\u1ebft $(2-x)^3=0$, gi\u00e1 tr\u1ecb c\u1ee7a $x$ l\u00e0 _input_","hint":"N\u1ebfu $a^3=0$ th\u00ec $a =0$. ","explain":"<span class='basic_left'>Ta c\u00f3: <br\/> $(2-x)^3=0 \\Rightarrow 2-x = 0 \\Rightarrow x = 2$ <br\/> <span class='basic_pink'> V\u1eady s\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $2$. <\/span><\/span> "}]}],"id_ques":438},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 v\u00e0o \u00f4 tr\u1ed1ng ","title_trans":"","temp":"fill_the_blank_random","correct":[[["1"],["-1"]]],"list":[{"point":5,"width":40,"type_input":"","ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai4/lv1/img\/4.jpg' \/><\/center>Bi\u1ebft $(4-4y^2)^3=0$, gi\u00e1 tr\u1ecb c\u1ee7a $y$ l\u00e0 _input_ ho\u1eb7c _input_","hint":"N\u1ebfu $a^3=0$ th\u00ec $a =0$. <br\/> N\u1ebfu $y^2=a^2$ th\u00ec $y =\\pm a.$ ","explain":"<span class='basic_left'> Ta c\u00f3: <br\/> $ {{\\left( 4-4{{y}^{2}} \\right)}^{3}}=0 \\\\ \\Leftrightarrow 4-4{{y}^{2}}=0 \\\\ \\Leftrightarrow 4{{y}^{2}} =4 \\\\ \\Leftrightarrow {{y}^{2}} =1 \\\\ \\Leftrightarrow y =\\pm 1$ <br\/> <span class='basic_pink'> V\u1eady s\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $1$ v\u00e0 $- 1$. <\/span><\/span> "}]}],"id_ques":439},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 v\u00e0o \u00f4 tr\u1ed1ng ","title_trans":"","temp":"fill_the_blank","correct":[[["3"]]],"list":[{"point":5,"width":40,"type_input":"","ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai4/lv1/img\/3.jpg' \/><\/center>Bi\u1ebft $(x-3)^3=0$, gi\u00e1 tr\u1ecb c\u1ee7a $x$ l\u00e0 _input_","hint":"N\u1ebfu $a^3=0$ th\u00ec $a =0$. ","explain":"<span class='basic_left'>Ta c\u00f3: <br\/> $(x-3)^3=0 \\Rightarrow x-3 = 0 \\Rightarrow x = 3$ <br\/> <span class='basic_pink'> Do \u0111\u00f3 ph\u1ea3i \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 3. <\/span><\/span> "}]}],"id_ques":440},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 v\u00e0o \u00f4 tr\u1ed1ng ","title_trans":"","temp":"fill_the_blank","correct":[[["216"]]],"list":[{"point":5,"width":40,"type_input":"","ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai4/lv1/img\/3.jpg' \/><\/center>Gi\u00e1 tr\u1ecb c\u1ee7a bi\u1ec3u th\u1ee9c $8{{x}^{3}}+12{{x}^{2}}y+6x{{y}^{2}}+{{y}^{3}}$ v\u1edbi $x = y = 2$ l\u00e0 _input_","hint":"R\u00fat g\u1ecdn bi\u1ec3u th\u1ee9c v\u1ec1 d\u1ea1ng l\u1eadp ph\u01b0\u01a1ng c\u1ee7a m\u1ed9t t\u1ed5ng. <br\/> Sau \u0111\u00f3 thay $x = y = 2$ v\u00e0o \u0111\u1ec3 t\u00ednh.","explain":"<span class='basic_left'>Ta c\u00f3: <br\/> $8{{x}^{3}}+12{{x}^{2}}y+6x{{y}^{2}}+{{y}^{3}}$$={{(2x)}^{3}}+3.{{\\left( 2x \\right)}^{2}}.y+3.2x.{{y}^{2}}+{{y}^{3}}$$={{\\left( 2x+y \\right)}^{3}}$ .<br\/> Thay $x = y = 2$ v\u00e0o bi\u1ec3u th\u1ee9c, ta \u0111\u01b0\u1ee3c: <br\/> ${{\\left( 2x+y \\right)}^{3}}={{\\left( 2.2+2 \\right)}^{3}}$$={{6}^{3}}=216$ <br\/> <span class='basic_pink'> V\u1eady s\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $216$. <\/span><\/span> "}]}],"id_ques":441},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 v\u00e0o \u00f4 tr\u1ed1ng ","title_trans":"","temp":"fill_the_blank","correct":[[["-1"]]],"list":[{"point":5,"width":40,"type_input":"","ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai4/lv1/img\/3.jpg' \/><\/center> Gi\u00e1 tr\u1ecb c\u1ee7a bi\u1ec3u th\u1ee9c $-{{x}^{3}}+3{{x}^{2}}-3x+1$ v\u1edbi $x = 2$ l\u00e0 _input_","hint":"R\u00fat g\u1ecdn bi\u1ec3u th\u1ee9c v\u1ec1 d\u1ea1ng l\u1eadp ph\u01b0\u01a1ng c\u1ee7a m\u1ed9t hi\u1ec7u. <br\/> Sau \u0111\u00f3 thay $x = 2$ v\u00e0o \u0111\u1ec3 t\u00ednh.","explain":"<span class='basic_left'>Ta c\u00f3: <br\/> $\\begin{align} & -{{x}^{3}}+3{{x}^{2}}-3x+1 \\\\ & =1-3x+3{{x}^{2}}-{{x}^{3}} \\\\ & ={{\\left( 1-x \\right)}^{3}} \\\\ \\end{align}$ .<br\/> Thay $x = 2$, ta \u0111\u01b0\u1ee3c: <br\/> ${{\\left( 1-x \\right)}^{3}}={{\\left( 1-2 \\right)}^{3}}={{\\left( -1 \\right)}^{3}}=-1$ <br\/> <span class='basic_pink'> V\u1eady s\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $-1$. <\/span><\/span> "}]}],"id_ques":442},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 v\u00e0o \u00f4 tr\u1ed1ng ","title_trans":"","temp":"fill_the_blank","correct":[[["1000"]]],"list":[{"point":5,"width":40,"type_input":"","ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai4/lv1/img\/1.png' \/><\/center>Gi\u00e1 tr\u1ecb c\u1ee7a bi\u1ec3u th\u1ee9c ${{x}^{3}}+12{{x}^{2}}+48x+64$ v\u1edbi $x = 6$ l\u00e0 _input_","hint":"R\u00fat g\u1ecdn bi\u1ec3u th\u1ee9c v\u1ec1 d\u1ea1ng l\u1eadp ph\u01b0\u01a1ng c\u1ee7a m\u1ed9t t\u1ed5ng. <br\/> Sau \u0111\u00f3 thay $x = 6$ v\u00e0o \u0111\u1ec3 t\u00ednh.","explain":"<span class='basic_left'>Ta c\u00f3: <br\/> ${{x}^{3}}+12{{x}^{2}}+48x+64={{x}^{3}}+3.{{x}^{2}}.4+3.x{{.4}^{2}}+{{4}^{3}}$$={{\\left( x+4 \\right)}^{3}}$ .<br\/> Thay $x = 6$, ta \u0111\u01b0\u1ee3c: <br\/> ${{\\left( x+4 \\right)}^{3}}={{\\left( 6+4 \\right)}^{3}}$$={{10}^{3}}=1000$ <br\/> <span class='basic_pink'> Do \u0111\u00f3 ph\u1ea3i \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $1000$. <\/span><\/span> "}]}],"id_ques":443},{"time":24,"part":[{"title":"\u0110i\u1ec1n d\u1ea5u $+$ ho\u1eb7c $-$ v\u00e0o \u00f4 tr\u1ed1ng \u0111\u1ec3 \u0111\u01b0\u1ee3c m\u1ed9t khai tri\u1ec3n \u0111\u00fang ","title_trans":"","temp":"fill_the_blank","correct":[[["-"],["+"],["-"]]],"list":[{"point":5,"width":40,"type_input":"","ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai4/lv1/img\/2.jpg' \/><\/center>${{\\left( x-4 \\right)}^{3}}$$={{x}^{3}}\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}12{{x}^{2}}\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}48x$$\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}64$","hint":"V\u1ebf tr\u00e1i l\u00e0 l\u1eadp ph\u01b0\u01a1ng c\u1ee7a m\u1ed9t hi\u1ec7u, do \u0111\u00f3 ta khai tri\u1ec3n theo h\u1eb1ng \u0111\u1eb3ng th\u1ee9c \u0111\u1ec3 t\u00ecm c\u00e1c d\u1ea5u c\u1ea7n \u0111i\u1ec1n.","explain":"<span class='basic_left'>Ta c\u00f3: <br\/> ${{\\left( x-4 \\right)}^{3}}={{x}^{3}}-12{{x}^{2}}+48x-64$ <br\/> <span class='basic_pink'> V\u1eady c\u00e1c d\u1ea5u c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u1ea7n l\u01b0\u1ee3t l\u00e0 $-, +$ v\u00e0 $\u2013$. <\/span><\/span> "}]}],"id_ques":444},{"time":24,"part":[{"title":"\u0110i\u1ec1n d\u1ea5u $+$ ho\u1eb7c $-$ v\u00e0o \u00f4 tr\u1ed1ng \u0111\u1ec3 \u0111\u01b0\u1ee3c m\u1ed9t khai tri\u1ec3n \u0111\u00fang ","title_trans":"","temp":"fill_the_blank","correct":[[["-"]]],"list":[{"point":5,"width":40,"type_input":"","ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai4/lv1/img\/4.jpg' \/><\/center>$-{{x}^{3}}+3{{x}^{2}}-3x+1$$=(1\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}x)^3$","explain":"<span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn<\/span><br\/>V\u1ebf tr\u00e1i l\u00e0 khai tri\u1ec3n h\u1eb1ng \u0111\u1eb3ng th\u1ee9c l\u1eadp ph\u01b0\u01a1ng c\u1ee7a m\u1ed9t hi\u1ec7u. <br\/><span class='basic_green'>B\u00e0i gi\u1ea3i<\/span><br\/>Ta c\u00f3: <br\/> $-{{x}^{3}}+3{{x}^{2}}-3x+1={{\\left( 1-x \\right)}^{3}}$<br\/> <span class='basic_pink'>V\u1eady s\u1ed1 d\u1ea5u \u0111i\u1ec1n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng d\u1ea5u $-$.<\/span><\/span> "}]}],"id_ques":445},{"time":24,"part":[{"title":"\u0110i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng \u0111\u1ec3 \u0111\u01b0\u1ee3c m\u1ed9t khai tri\u1ec3n \u0111\u00fang ","title_trans":"","temp":"fill_the_blank","correct":[[["3a"],["1"]]],"list":[{"point":5,"width":40,"type_input":"","ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai4/lv1/img\/4.jpg' \/><\/center>$(a+1)^3$$=a^3+3a^2+\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}+\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}$","explain":"<span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/><b>B\u01b0\u1edbc 1:<\/b> Khai tri\u1ec3n v\u1ebf tr\u00e1i theo h\u1eb1ng \u0111\u1eb3ng th\u1ee9c l\u1eadp ph\u01b0\u01a1ng c\u1ee7a m\u1ed9t t\u1ed5ng <br\/> <b>B\u01b0\u1edbc 2:<\/b>V\u00ec VT = VP n\u00ean suy ra \u0111\u01b0\u1ee3c c\u00e1c h\u1ea1ng t\u1eed c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng <br\/><span class='basic_green'>B\u00e0i gi\u1ea3i<\/span><br\/>Ta c\u00f3: <br\/> $VT = (a+1)^3=a^3+3a^2+3a+1$. <br\/> V\u00ec $VT = VP$<br\/> $\\Rightarrow$ \u0110\u00e1p \u00e1n c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 <span class='basic_pink'> $3a$ v\u00e0 $1$.<\/span><\/span> "}]}],"id_ques":446},{"time":24,"part":[{"title":"\u0110i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng \u0111\u1ec3 \u0111\u01b0\u1ee3c m\u1ed9t khai tri\u1ec3n \u0111\u00fang ","title_trans":"","temp":"fill_the_blank","correct":[[["y"],["2"],["y"]]],"list":[{"point":5,"width":40,"type_input":"","ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai4/lv1/img\/1.png' \/><\/center>$(y-x)^3$$=y^3-3.{\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}}^\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}.x$$+3\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}.x^2-x^3$","explain":"<span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn<\/span><br\/><b>B\u01b0\u1edbc 1:<\/b> Khai tri\u1ec3n v\u1ebf tr\u00e1i theo h\u1eb1ng \u0111\u1eb3ng th\u1ee9c: $(a-b)^3=a^3-3a^2b+3ab^2-b^3$. <br\/> <b>B\u01b0\u1edbc 2:<\/b> V\u00ec VT = VP n\u00ean suy ra \u0111\u01b0\u1ee3c c\u00e1c h\u1ea1ng t\u1eed c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng. <br\/><span class='basic_green'>B\u00e0i gi\u1ea3i<\/span><br\/>Ta c\u00f3: <br\/> $VT = {{\\left( y-x \\right)}^{3}} ={{y}^{3}}-3{{y}^{2}}x+3y{{x}^{2}}-{{x}^{3}}$ <br\/> V\u00ec $VT = VP$ $\\Rightarrow$ \u0110\u00e1p \u00e1n c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0: <span class='basic_pink'> $y^2$ v\u00e0 $y$.<\/span><\/span> "}]}],"id_ques":447},{"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":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai4/lv1/img\/3.jpg' \/><\/center>Khai tri\u1ec3n $(3x-1)^3$ theo h\u1eb1ng \u0111\u1eb3ng th\u1ee9c ta \u0111\u01b0\u1ee3c:","select":["A. $9x^3-27x^2+9x-1$ ","B. $-27x^3+27x^2-9x+1$ ","C. $27x^3-1$","D. $27x^3-27x^2+9x-1$"],"explain":"<span class='basic_left'>Ta c\u00f3:<br\/> $(3x-1)^3 =(3x)^3-3.(3x)^2.1+3.3x.1^2-1^3 =27x^3-27x^2+9x-1$ <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 D.<\/span>","column":2}]}],"id_ques":448},{"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":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai4/lv1/img\/2.jpg' \/><\/center>Khai tri\u1ec3n $(1-a)^3$ theo h\u1eb1ng \u0111\u1eb3ng th\u1ee9c ta \u0111\u01b0\u1ee3c:","select":["A. $1+3a+3a^2-a^3$ ","B. $1-3a+3a^2-a^3$ ","C. $1-2a+a^3$","D. $1-3a+a^3$"],"hint":"\u00c1p d\u1ee5ng h\u1eb1ng \u0111\u1eb3ng th\u1ee9c: $(a-b)^3=a^3-3a^2b+3ab^2-b^3$.","explain":"<span class='basic_left'>Ta c\u00f3:<br\/> $(1-a)^3=1^3-3.1^2.a+3.1.a^2-a^3$$=1-3a+3a^2-a^3$ <br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 B.<\/span>","column":2}]}],"id_ques":449},{"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":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai4/lv1/img\/2.jpg' \/><\/center>Khai tri\u1ec3n $(x+1)^3$ theo h\u1eb1ng \u0111\u1eb3ng th\u1ee9c ta \u0111\u01b0\u1ee3c:","select":["A. $x^3+3x+1$ ","B. $x^3+2x+1$ ","C. $x^3+3x^2+3x+1$","D. $x^2+2x+1$"],"hint":"\u00c1p d\u1ee5ng h\u1eb1ng \u0111\u1eb3ng th\u1ee9c: $(a+b)^3=a^3+3a^2b+3ab^2+b^3$.","explain":"<span class='basic_left'>Ta c\u00f3:<br\/> $(x+1)^3=x^3+3.x^2.1+3.x.1^2+1^3 =x^3+3x^2+3x+1$ <br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 C.<\/span>","column":2}]}],"id_ques":450}],"lesson":{"save":0,"level":1}}