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{"segment":[{"time":24,"part":[{"title":"\u0110i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng ","title_trans":"","temp":"fill_the_blank_random","correct":[[["2016"],["n"]]],"list":[{"point":10,"width":40,"type_input":"","ques":"B\u1eadc c\u1ee7a \u0111a th\u1ee9c $F=x\\left( {{x}^{n}}+1 \\right)+{{x}^{2}}\\left( {{x}^{n}}+1 \\right)+...+{{x}^{2016}}\\left( {{x}^{n}}+1 \\right)$ l\u00e0: <br\/> $\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}+\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}$","hint":"","explain":"<span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> <b>B\u01b0\u1edbc 1:<\/b> R\u00fat g\u1ecdn $F$, \u00e1p d\u1ee5ng nh\u00e2n \u0111\u01a1n th\u1ee9c v\u1edbi \u0111a th\u1ee9c: $a(b+c)=a.b+a.c$<br\/> <b>B\u01b0\u1edbc 2:<\/b> S\u1eafp x\u1ebfp theo th\u1ee9 t\u1ef1 l\u0169y th\u1eeba t\u0103ng d\u1ea7n \u0111\u1ec3 t\u00ecm b\u1eadc c\u1ee7a \u0111a th\u1ee9c. <br\/><span class='basic_green'>B\u00e0i gi\u1ea3i<\/span><br\/>Ta c\u00f3:<br\/> $ F=x\\left( {{x}^{n}}+1 \\right)+{{x}^{2}}\\left( {{x}^{n}}+1 \\right)+...+{{x}^{2016}}\\left( {{x}^{n}}+1 \\right) \\\\ ={{x}^{1+n}}+x+{{x}^{2+n}}+{{x}^{2}}+...+{{x}^{2016+n}}+{{x}^{2016}} \\\\ =x+{{x}^{2}}+...+{{x}^{2016}}+{{x}^{1+n}}+{{x}^{2+n}}+...+{{x}^{2016+n}}$<br\/> B\u1eadc c\u1ee7a \u0111a th\u1ee9c $F$ l\u00e0 $2016 + n$.<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n c\u1ea7n \u0111i\u1ec1n l\u00e0 $2016$ v\u00e0 $n$.<\/span><\/span> "}]}],"id_ques":321},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[2]],"list":[{"point":10,"ques":"H\u1ec7 s\u1ed1 cao nh\u1ea5t trong \u0111a th\u1ee9c $B=4{{x}^{2}}\\left( 5-12x \\right)-x\\left( 4{{x}^{5}}-1 \\right)$ l\u00e0: ","select":["A. $12$","B. $-4$","C. $20$","D. $-48$"],"hint":"","explain":"<span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn<\/span><br\/> <b>B\u01b0\u1edbc 1:<\/b> Nh\u00e2n \u0111\u01a1n th\u1ee9c v\u1edbi \u0111a th\u1ee9c.<br\/> <b>B\u01b0\u1edbc 2:<\/b> S\u1eafp x\u1ebfp \u0111a th\u1ee9c theo l\u0169y th\u1eeba gi\u1ea3m d\u1ea7n c\u1ee7a bi\u1ebfn v\u00e0 t\u00ecm l\u0169y th\u1eeba b\u1eadc cao nh\u1ea5t c\u1ee7a bi\u1ebfn trong \u0111a th\u1ee9c \u0111\u00f3.<br\/> <b>B\u01b0\u1edbc 3:<\/b> H\u1ec7 s\u1ed1 \u0111i v\u1edbi l\u0169y th\u1eeba b\u1eadc cao nh\u1ea5t c\u1ee7a bi\u1ebfn l\u00e0 h\u1ec7 s\u1ed1 cao nh\u1ea5t c\u1ea7n t\u00ecm.<br\/><span class='basic_green'>Gi\u1ea3i<\/span><br\/>Ta c\u00f3:<br\/>$\\begin{align}& B=4{{x}^{2}}\\left( 5-12x \\right)-x\\left( 4{{x}^{5}}-1 \\right) \\\\ & =20{{x}^{2}}-48{{x}^{3}}-4{{x}^{6}}+x \\\\ & =-4{{x}^{6}}-48{{x}^{3}}+20{{x}^{2}}+x \\\\ \\end{align}$<br\/> \u0110a th\u1ee9c c\u00f3 l\u0169y th\u1eeba b\u1eadc cao nh\u1ea5t c\u1ee7a bi\u1ebfn l\u00e0 $x^6$.<br\/> H\u1ec7 s\u1ed1 \u0111i v\u1edbi $x^6$ l\u00e0 $-4$ <br\/> Do \u0111\u00f3 h\u1ec7 s\u1ed1 cao nh\u1ea5t trong \u0111a th\u1ee9c B l\u00e0 $-4$ <br\/><span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n l\u00e0 B.<\/span> ","column":2}]}],"id_ques":322},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[3]],"list":[{"point":10,"ques":"Bi\u1ebft $4x\\left( 3x+2 \\right)-6x\\left( 2x+5 \\right)+21\\left( x-1 \\right)=0$, gi\u00e1 tr\u1ecb c\u1ee7a $x$ t\u00ecm \u0111\u01b0\u1ee3c l\u00e0: ","select":["A. $5$","B. $17$","C. $-21$","D. $-12$"],"hint":"","explain":"<span class='basic_left'>Ta c\u00f3:<br\/>$ 4x\\left( 3x+2 \\right)-6x\\left( 2x+5 \\right)+21\\left( x-1 \\right) =0 \\\\ \\Leftrightarrow 12{{x}^{2}}+8x-12{{x}^{2}}-30x+21x-21=0 \\\\ \\Leftrightarrow -x-21=0 \\\\ \\Leftrightarrow x=-21 $<br\/> <span class='basic_pink'> V\u1eady gi\u00e1 tr\u1ecb $x$ c\u1ea7n t\u00ecm l\u00e0 $- 21$.<\/span>","column":2}]}],"id_ques":323},{"time":24,"part":[{"title":"\u0110i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng ","title_trans":"","temp":"fill_the_blank","correct":[[["4"]]],"list":[{"point":10,"width":40,"type_input":"","ques":"H\u1ec7 s\u1ed1 c\u1ee7a ${{x}^{3}}$ trong \u0111a th\u1ee9c $M=x\\left( {{x}^{2}}+3x+2 \\right)-{{x}^{2}}\\left( 1-3x+4{{x}^{2}}+{{x}^{3}} \\right)$ l\u00e0 _input_","hint":"","explain":"<span class='basic_left'>Ta c\u00f3:<br\/> $ M=x\\left( {{x}^{2}}+3x+2 \\right)-{{x}^{2}}\\left( 1-3x+4{{x}^{2}}+{{x}^{3}} \\right) \\\\ ={{x}^{3}}+3{{x}^{2}}+2x-{{x}^{2}}+3{{x}^{3}}-4{{x}^{4}}-{{x}^{5}} \\\\ =-{{x}^{5}}-4{{x}^{4}}+4{{x}^{3}}+2{{x}^{2}}+2x $<br\/> H\u1ec7 s\u1ed1 \u0111i v\u1edbi $x^3$ l\u00e0 $4$. <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n c\u1ea7n \u0111i\u1ec1n l\u00e0 $4$.<\/span> "}]}],"id_ques":324},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[3]],"list":[{"point":10,"ques":"Gi\u00e1 tr\u1ecb c\u1ee7a bi\u1ec3u th\u1ee9c $B=5x\\left( x-4y \\right)-4y\\left( y-5x \\right)$ v\u1edbi $x=-\\dfrac{1}{5};y=-\\dfrac{1}{2}$ l\u00e0 ","select":["A. $-\\dfrac{2}{3}$","B. $-\\dfrac{3}{4}$ ","C. $-\\dfrac{4}{5}$ ","D. $-\\dfrac{5}{6}$ "],"hint":"Bi\u1ebfn \u0111\u1ed5i v\u00e0 r\u00fat g\u1ecdn bi\u1ec3u th\u1ee9c \u0111\u00e3 cho.<br\/> Thay c\u00e1c gi\u00e1 tr\u1ecb $x, y$ \u0111\u1ec1 b\u00e0i \u0111\u00e3 cho v\u00e0o bi\u1ec3u th\u1ee9c \u0111\u00e3 r\u00fat g\u1ecdn.","explain":"<span class='basic_left'> Ta c\u00f3: <br\/>$B=5x\\left( x-4y \\right)-4y\\left( y-5x \\right)$<br\/>$=5{{x}^{2}}-20xy-4{{y}^{2}}+20xy$<br\/>$=5{{x}^{2}}-4{{y}^{2}}$<br\/>V\u1edbi $x=-\\dfrac{1}{5};y=-\\dfrac{1}{2}$ th\u00ec: <br\/> $B=5.\\dfrac{1}{25}-4.\\dfrac{1}{4}$ $=-\\dfrac{4}{5}$ <br\/><span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span>","column":2}]}],"id_ques":325},{"time":24,"part":[{"title":"Kh\u1eb3ng \u0111\u1ecbnh sau \u0111\u00e2y \u0111\u00fang hay sai","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":10,"ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai1/lv3/img\/1.png' \/><\/center>N\u1ebfu $(2a+b)\\,\\,\\,\\,\\vdots \\,\\,13\\,\\,\\,;\\,\\,(5a-4b)\\,\\,\\,\\,\\vdots \\,\\,\\,13$ th\u00ec $(a-6b)\\,\\,\\,\\,\\vdots \\,\\,\\,\\,13$. \u0110\u00fang hay sai? ","select":["\u0110\u00fang","Sai"],"explain":"<span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn<\/span><br\/> <b>B\u01b0\u1edbc 1:<\/b> T\u00ednh $(5a-4b)-2(2a+b)$ <br\/> <b>B\u01b0\u1edbc 2:<\/b> L\u1eadp lu\u1eadn \u0111\u1ec3 ch\u1ee9ng t\u1ecf $(5a-4b)-2(2a+b)$ chia h\u1ebft cho 13. <br\/><span class='basic_green'>Gi\u1ea3i<\/span><br\/><span class='basic_left'>Theo b\u00e0i $(2a+b)\\,\\,\\,\\,\\vdots \\,\\,\\,13 \\Rightarrow 2\\left( 2a+b\\right)=(4a+2b)\\,\\,\\,\\,\\vdots \\,\\,\\,\\,13$ (1)<br\/>M\u00e0 $(5a-4b)\\,\\,\\,\\,\\vdots \\,\\,\\,13$ (2)<br\/>K\u1ebft h\u1ee3p (1) v\u00e0 (2) c\u00f3: $\\left\\{ \\begin{align}& (5a-4b)\\,\\,\\,\\vdots \\,\\,\\,13 \\\\ & (4a+2b)\\,\\,\\,\\,\\vdots \\,\\,\\,13 \\\\ \\end{align} \\right. \\Rightarrow \\left( 5a-4b \\right)-\\left( 4a+2b \\right)=(a-6b)\\,\\,\\,\\vdots \\,\\,\\,13$<span><br\/> <span class='basic_pink'> V\u1eady kh\u1eb3ng \u0111\u1ecbnh tr\u00ean l\u00e0: \u0110\u00fang.<\/span>","column":2}]}],"id_ques":326},{"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"],["2"],["-3"]]],"list":[{"point":10,"width":40,"content":"","type_input":"","ques":"T\u00ecm c\u00e1c h\u1ec7 s\u1ed1 $a, b, c$ bi\u1ebft r\u1eb1ng $3{{x}^{2}}\\left( a\\,{{x}^{2}}-2bx-3c \\right)=3{{x}^{4}}-12{{x}^{3}}+27{{x}^{2}}$ v\u1edbi m\u1ecdi $x$. <br\/> <b>\u0110\u00e1p \u00e1n:<\/b> $\\left\\{ \\begin{align}& a=\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{} \\\\ & b= \\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{} \\\\ & c= \\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}\\\\ \\end{align} \\right.$ ","hint":"Bi\u1ebfn \u0111\u1ed5i v\u1ebf tr\u00e1i. <br\/> S\u1eed d\u1ee5ng \u0111\u1ed3ng nh\u1ea5t h\u1ec7 s\u1ed1 2 v\u1ebf \u0111\u1ec3 t\u00ecm $a, b, c$.","explain":"<span class='basic_left'>Ta c\u00f3: $3{{x}^{2}}\\left( a\\,{{x}^{2}}-2bx-3c \\right) =3{{x}^{4}}-12{{x}^{3}}+27{{x}^{2}}$ <br\/>$3a\\,{{x}^{4}}-6b{{x}^{3}}-9c{{x}^{2}} =3{{x}^{4}}-12{{x}^{3}}+27{{x}^{2}}$<br\/> \u0110\u1ed3ng nh\u1ea5t h\u1ec7 s\u1ed1 hai v\u1ebf, ta \u0111\u01b0\u1ee3c: <br\/> $ \\left\\{ \\begin{align}& 3a=3 \\\\ & -6b=-12 \\\\ & -9c=27 \\\\ \\end{align} \\right.$<br\/> $\\Leftrightarrow \\left\\{ \\begin{align}& a=1 \\\\ & b=2 \\\\ & c=-3 \\\\ \\end{align} \\right.$ <br\/><span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n c\u1ea7n \u0111i\u1ec1n v\u00e0o c\u00e1c \u00f4 l\u00e0 $1; 2; - 3$.<\/span><\/span>"}]}],"id_ques":327},{"time":24,"part":[{"title":"Kh\u1eb3ng \u0111\u1ecbnh sau \u0111\u00e2y \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":10,"ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai1/lv3/img\/1.png' \/><\/center>Gi\u00e1 tr\u1ecb c\u1ee7a bi\u1ec3u th\u1ee9c $M=3x\\left( x-5y \\right)+\\left( y-5x \\right)\\left( -3y \\right)$$-3\\left( {{x}^{2}}-{{y}^{2}} \\right)-1$ kh\u00f4ng ph\u1ee5 thu\u1ed9c v\u00e0o c\u00e1c bi\u1ebfn $x, y$. \u0110\u00fang hay sai?","select":["\u0110\u00fang","Sai"],"hint":"<br\/>Bi\u1ebfn \u0111\u1ed5i, r\u00fat g\u1ecdn bi\u1ec3u th\u1ee9c $M$. <br\/> \u00c1p d\u1ee5ng: nh\u00e2n \u0111\u01a1n th\u1ee9c v\u1edbi t\u1eebng h\u1ea1ng t\u1eed c\u1ee7a \u0111a th\u1ee9c: $a(b+c) = a.b+a.c$<br\/>N\u1ebfu k\u1ebft qu\u1ea3 r\u00fat g\u1ecdn $M$ kh\u00f4ng ch\u01b0a c\u00e1c bi\u1ebfn $x, y$ th\u00ec gi\u00e1 tr\u1ecb $M$ kh\u00f4ng ph\u1ee5 thu\u1ed9c v\u00e0o $x, y$ v\u00e0 ng\u01b0\u1ee3c l\u1ea1i.","explain":"<span class='basic_left'>Ta c\u00f3:<br\/>$ M=3x\\left( x-5y \\right)+\\left( y-5x \\right)\\left( -3y \\right)-3\\left( {{x}^{2}}-{{y}^{2}} \\right)-1 \\\\ =3{{x}^{2}}-15xy-3{{y}^{2}}+15xy-3{{x}^{2}}+3{{y}^{2}}-1 \\\\ =-1 $<br\/>Gi\u00e1 tr\u1ecb c\u1ee7a $M$ kh\u00f4ng ph\u1ee5 thu\u1ed9c v\u00e0o c\u00e1c bi\u1ebfn $x, y$.<br\/> <span class='basic_pink'> V\u1eady kh\u1eb3ng \u0111\u1ecbnh tr\u00ean l\u00e0 \u0110\u00fang.<\/span>","column":2}]}],"id_ques":328},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":10,"ques":"Bi\u1ebft $2{{x}^{3}}\\left( 2x-3 \\right)$$-{{x}^{2}}\\left( 4{{x}^{2}}-6x+2 \\right)=0$, gi\u00e1 tr\u1ecb c\u1ee7a $x$ l\u00e0:","select":["A. $x = 0$ ","B. $x = 1$","C. $x = 2$","D. $x = -2$"],"hint":"Bi\u1ebfn \u0111\u1ed5i, r\u00fat g\u1ecdn gi\u1ea3 thi\u1ebft \u0111\u1ec3 t\u00ecm $x$.<br\/>\u00c1p d\u1ee5ng: nh\u00e2n \u0111\u01a1n th\u1ee9c v\u1edbi t\u1eebng h\u1ea1ng t\u1eed c\u1ee7a \u0111a th\u1ee9c: $a(b+c) = a.b+a.c$","explain":"<span class='basic_left'> Ta c\u00f3: <br\/> $2{{x}^{3}}\\left( 2x-3 \\right) -{{x}^{2}}\\left( 4{{x}^{2}}-6x+2 \\right)=0 \\\\ \\Leftrightarrow 4{{x}^{4}}-6{{x}^{3}} -4{{x}^{4}}+6{{x}^{3}}-2{{x}^{2}}=0 \\\\ \\Leftrightarrow -2{{x}^{2}}=0 \\\\ \\Leftrightarrow x=0$ <br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 A. <\/span>","column":2}]}],"id_ques":329},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[2]],"list":[{"point":10,"ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai1/lv3/img\/1.png' \/><\/center>K\u1ebft qu\u1ea3 ph\u00e9p nh\u00e2n $\\left( \\dfrac{1}{2}{{a}^{3}}{{b}^{2}}-\\dfrac{3}{4}a{{b}^{4}} \\right)\\left( \\dfrac{4}{3}{{a}^{3}}b \\right)$ l\u00e0:","select":["A. $\\dfrac{2}{3}{{a}^{5}}{{b}^{3}}-{{a}^{4}}{{b}^{5}}$ ","B. $\\dfrac{2}{3}{{a}^{6}}{{b}^{3}}-{{a}^{4}}{{b}^{5}}$ ","C. $\\dfrac{4}{3}{{a}^{9}}{{b}^{2}}-{{a}^{3}}{{b}^{4}}$","D. $\\dfrac{4}{3}{{a}^{9}}{{b}^{3}}+{{a}^{3}}{{b}^{4}}$"],"hint":"","explain":"<span class='basic_left'> Ta c\u00f3: $\\left( \\dfrac{1}{2}{{a}^{3}}{{b}^{2}}-\\dfrac{3}{4}a{{b}^{4}} \\right)\\left( \\dfrac{4}{3}{{a}^{3}}b \\right) =\\dfrac{2}{3}{{a}^{6}}{{b}^{3}}-{{a}^{4}}{{b}^{5}}$ <br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B. <\/span>","column":2}]}],"id_ques":330}],"lesson":{"save":0,"level":3}}

Điểm của bạn.

Câu hỏi này theo dạng chọn đáp án đúng, sau khi đọc xong câu hỏi, bạn bấm vào một trong số các đáp án mà chương trình đưa ra bên dưới, sau đó bấm vào nút gửi để kiểm tra đáp án và sẵn sàng chuyển sang câu hỏi kế tiếp

Trả lời đúng trong khoảng thời gian quy định bạn sẽ được + số điểm như sau:
Trong khoảng 1 phút đầu tiên + 5 điểm
Trong khoảng 1 phút -> 2 phút + 4 điểm
Trong khoảng 2 phút -> 3 phút + 3 điểm
Trong khoảng 3 phút -> 4 phút + 2 điểm
Trong khoảng 4 phút -> 5 phút + 1 điểm

Quá 5 phút: không được cộng điểm

Tổng thời gian làm mỗi câu (không giới hạn)

Điểm của bạn.

Bấm vào đây nếu phát hiện có lỗi hoặc muốn gửi góp ý