{"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}}