{"segment":[{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 v\u00e0o \u00f4 tr\u1ed1ng ","title_trans":"","temp":"fill_the_blank","correct":[[["5"]]],"list":[{"point":5,"width":40,"type_input":"","ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai10/lv1/img\/5.jpg' \/><\/center> Ph\u00e9p chia $[(4x^2-16)x+5]:(2x-4)$ c\u00f3 d\u01b0 l\u00e0 _input_","hint":" X\u00e9t $(4x^2-16)x$ c\u00f3 chia h\u1ebft cho $2x-4$ kh\u00f4ng, $5$ c\u00f3 chia h\u1ebft cho $2x-4$ kh\u00f4ng.<br\/> N\u1ebfu $a\\,\\vdots\\, m; b\\, \\vdots \\, m$ th\u00ec $(a+b) \\,\\vdots \\, m$.<br\/> N\u1ebfu $a\\,\\vdots\\, m; b\\, \\not\\vdots \\, m$ th\u00ec $(a+b) \\,\\not\\vdots \\, m$","explain":"<span class='basic_left'> Ta c\u00f3:<br\/> $\\begin{aligned} & \\left( 4{{x}^{2}}-16 \\right)x=\\left( 2x+4 \\right)\\left( 2x-4 \\right)x \\\\ & \\text{Do} \\,\\,\\left( 2x-4 \\right)\\,\\,\\,\\vdots \\,\\,\\,\\left( 2x-4 \\right)\\,\\,\\Rightarrow \\,\\,\\left( 2x+4 \\right)\\left( 2x-4 \\right)x\\,\\,\\,\\vdots \\,\\,\\,\\left( 2x-4 \\right) \\\\ & \\left. \\begin{aligned} & \\text{V\u00ec} \\hspace{0,2cm} \\left( 4{{x}^{2}}-16 \\right)x\\vdots \\,\\,\\,\\left( 2x-4 \\right) \\\\ & \\text{Nh\u01b0ng} \\hspace{0,2cm} 5\\,\\,\\,\\,\\not\\vdots \\,\\,\\,\\left( 2x-4 \\right) \\\\ \\end{aligned} \\right\\}\\\\& \\Rightarrow \\left[ \\left( 4{{x}^{2}}-16 \\right)x+5 \\right]\\,\\,\\,:\\,\\,\\,\\left( 2x-4 \\right)\\,\\,\\,\\text{d\u01b0 }\\,\\,5 \\\\ \\end{aligned}$ <br\/> Ph\u00e9p chia c\u00f3 d\u01b0 l\u00e0 $5$. <br\/> <span class='basic_pink'> Do \u0111\u00f3 ph\u1ea3i \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $5$. <\/span><\/span> "}]}],"id_ques":731},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 v\u00e0o \u00f4 tr\u1ed1ng ","title_trans":"","temp":"fill_the_blank","correct":[[["0"]]],"list":[{"point":5,"width":40,"type_input":"","ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai10/lv1/img\/5.jpg' \/><\/center> Ph\u00e9p chia $(2x^3-27x^2+115x-150):(x-5)$ c\u00f3 d\u01b0 l\u00e0 _input_","hint":" \u0110\u1eb7t ph\u00e9p chia v\u00e0 t\u00ecm s\u1ed1 d\u01b0.","explain":"<span class='basic_left'> \u0110\u1eb7t ph\u00e9p chia: <br\/>$\\left. \\begin{align} & \\begin{matrix} 2{{x}^{3}}-27{{x}^{2}}+115x-150\\,\\,\\,\\, \\\\ 2{{x}^{3}}-10{{x}^{2}}\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\, \\\\\\end{matrix} \\\\ & \\overline{\\begin{align} & \\,\\,\\,\\,\\,\\,\\,\\,-17{{x}^{2}}+115x-150\\,\\,\\,\\,\\, \\\\ & \\,\\,\\,\\,\\,\\,\\,\\,-17{{x}^{2}}+85x\\,\\, \\\\ & \\,\\,\\,\\,\\,\\,\\,\\,\\,\\overline{\\begin{align} & \\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,30x-150\\,\\,\\,\\,\\,\\, \\\\ & \\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,30x-150 \\\\ & \\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\overline{\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,0\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,} \\\\ \\end{align}} \\\\ \\end{align}} \\\\ \\end{align} \\right|\\begin{matrix} \\dfrac{x-5}{2{{x}^{2}}-17x+30} \\\\ \\begin{matrix} \\begin{matrix} \\begin{matrix} {} \\\\ {} \\\\\\end{matrix} \\\\ {} \\\\\\end{matrix} \\\\ {} \\\\\\end{matrix} \\\\ {} \\\\\\end{matrix}$ <br\/> Ph\u00e9p chia c\u00f3 d\u01b0 l\u00e0 $0$. <br\/> <span class='basic_pink'> Do \u0111\u00f3 ph\u1ea3i \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $0$. <\/span><\/span> "}]}],"id_ques":732},{"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/bai10/lv1/img\/4.jpg' \/><\/center> T\u00ecm $n$ $( n\\,\\in\\,\\mathbb{Z})$ \u0111\u1ec3 ph\u00e9p chia sau l\u00e0 ph\u00e9p chia h\u1ebft:<br\/> $10x^5y^4z^3:x^{2-n}y^4z$ ","select":["A. $n\\,\\in\\,\\mathbb{Z};\\,n \\ge 0 $","B. $n\\,\\in\\,\\mathbb{Z};\\,n \\ge 1 $","C. $n\\,\\in\\,\\mathbb{Z};\\,n \\ge -1$","D. $n\\,\\in\\,\\mathbb{Z};\\,n \\ge -3$"],"hint":"","explain":"<span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn<\/span><br\/> <b> Quy t\u1eafc:<\/b> \u0110\u1ec3 $ax^my^n$ chia h\u1ebft cho $bx^py^q$ th\u00ec $\\left\\{ \\begin{align} & m\\ge p \\\\ & n\\ge q \\\\ \\end{align} \\right.$ <br\/><span class='basic_green'>Gi\u1ea3i<\/span><br\/><span class='basic_left'>\u0110\u1ec3 $10x^5y^4z^3:x^{2-n}y^4z$ l\u00e0 ph\u00e9p chia h\u1ebft th\u00ec $5\\ge 2-n\\Leftrightarrow n\\ge -3$ v\u1edbi $n\\in \\mathbb{Z}$ <span><br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 D.<\/span>","column":2}]}],"id_ques":733},{"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/bai10/lv1/img\/3.jpg' \/><\/center> T\u00ecm $n$ $( n\\,\\in\\,\\mathbb{N})$ \u0111\u1ec3 ph\u00e9p chia sau l\u00e0 ph\u00e9p chia h\u1ebft:<br\/> $\\dfrac{1}{2}x^{n+1}y^2:xy$ ","select":["A. $n\\,\\in\\,\\mathbb{N};\\,n \\ge 0 $","B. $n\\,\\in\\,\\mathbb{N};\\,n \\ge 1 $","C. $n\\,\\in\\,\\mathbb{N};\\,n \\le 0$","D. $n\\,\\in\\,\\mathbb{N};\\,n \\le 1$"],"hint":"","explain":"<span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn<\/span><br\/> <b> Quy t\u1eafc:<\/b> \u0110\u1ec3 $ax^my^n$ chia h\u1ebft cho $bx^py^q$ th\u00ec $\\left\\{ \\begin{align} & m\\ge p \\\\ & n\\ge q \\\\ \\end{align} \\right.$ <br\/><span class='basic_green'>Gi\u1ea3i<\/span><br\/><span class='basic_left'>\u0110\u1ec3 $\\dfrac{1}{2}x^{n+1}y^2:xy$ l\u00e0 ph\u00e9p chia h\u1ebft th\u00ec $n+1\\ge 1\\Leftrightarrow n\\ge 0$ v\u1edbi $n\\in \\mathbb{N}$ <span><br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 A.<\/span>","column":2}]}],"id_ques":734},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 v\u00e0o \u00f4 tr\u1ed1ng trong ph\u00e9p chia sau ","title_trans":"","temp":"fill_the_blank","correct":[[["4"],["3"],["x"]]],"list":[{"point":5,"width":50,"type_input":"","ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai10/lv1/img\/2.jpg' \/><\/center> $(20x^3y^4-15x^2y^5+3x^3y^3):5x^2y^3=\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}xy$$-\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}y^2$$+\\dfrac{3}{5}\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}$","hint":" Th\u1ef1c hi\u1ec7n ph\u00e9p chia \u0111a th\u1ee9c cho \u0111\u01a1n th\u1ee9c (trong tr\u01b0\u1eddng h\u1ee3p c\u00e1c h\u1ea1ng t\u1eed c\u1ee7a \u0111a th\u1ee9c \u0111\u1ec1u chia h\u1ebft cho \u0111\u01a1n th\u1ee9c):<br\/> <b> $(A+ B+C):D=A:D+B:D+C:D$ <\/b>","explain":"<span class='basic_left'> $\\begin{align} & (20{{x}^{3}}{{y}^{4}}-15{{x}^{2}}{{y}^{5}}+3{{x}^{3}}{{y}^{3}}):5{{x}^{2}}{{y}^{3}} \\\\ & =20{{x}^{3}}{{y}^{4}}:5{{x}^{2}}{{y}^{3}}-15{{x}^{2}}{{y}^{5}}:5{{x}^{2}}{{y}^{3}}+3{{x}^{3}}{{y}^{3}}:5{{x}^{2}}{{y}^{3}} \\\\ & =4xy-3{{y}^{2}}+\\dfrac{3}{5}x \\\\ \\end{align}$ . <br\/> <span class='basic_pink'> Do \u0111\u00f3 ph\u1ea3i \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $4$, 3 v\u00e0 $x$. <\/span><\/span> "}]}],"id_ques":735},{"time":24,"part":[{"title":"Ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"select":["A. $\\dfrac{1}{6}y^2$","B. $\\dfrac{1}{3}y^2$","C. $\\dfrac{1}{2}y^2$"],"ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai10/lv1/img\/2.jpg' \/><\/center> $\\dfrac{1}{2}x^2y^3z:3x^2yz=?$","hint":"","explain":"<span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> Th\u1ef1c hi\u1ec7n ph\u00e9p chia \u0111\u01a1n th\u1ee9c cho \u0111\u01a1n th\u1ee9c:<br\/> + H\u1ec7 s\u1ed1 chia h\u1ec7 s\u1ed1 <br\/> + Chia l\u0169y th\u1eeba c\u1ee7a t\u1eebng bi\u1ebfn trong \u0111\u01a1n th\u1ee9c n\u00e0y cho l\u0169y th\u1eeba c\u1ee7a t\u1eebng bi\u1ebfn trong \u0111\u01a1n th\u1ee9c kia.<br\/> + Nh\u00e2n c\u00e1c k\u1ebft qu\u1ea3 v\u1eeba t\u00ecm \u0111\u01b0\u1ee3c v\u1edbi nhau.<br\/><span class='basic_green'>B\u00e0i gi\u1ea3i<\/span><br\/> $\\dfrac{1}{2}x^2y^3z:3x^2yz=\\dfrac{1}{6}y^2$.<\/span> "}]}],"id_ques":736},{"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/bai10/lv1/img\/16.jpg' \/><\/center> Ph\u00e2n t\u00edch \u0111a th\u1ee9c $81x^2-64y^2$ th\u00e0nh nh\u00e2n t\u1eed \u0111\u01b0\u1ee3c k\u1ebft qu\u1ea3 l\u00e0: ","select":["A. $(9x-8y)^2$ ","B. $(9x+8y)(9x-8y)$","C. $(3x-4y)^2$","D. $(9x+8y)^2$"],"hint":" Vi\u1ebft l\u1ea1i $81x^2-64y^2=(9x)^2-(8y)^2$, s\u1eed d\u1ee5ng h\u1eb1ng \u0111\u1eb3ng th\u1ee9c \u0111\u1ec3 ph\u00e2n t\u00edch th\u00e0nh nh\u00e2n t\u1eed. ","explain":"<span class='basic_left'> Ta c\u00f3: <br\/> $\\begin{align} & 81x^2-64y^2 \\\\ & =(9x)^2-(8y)^2 \\\\ & =(9x+8y)(9x-8y) \\\\ \\end{align}$ <br\/> <span class='basic_pink'> V\u1eady ch\u1ecdn \u0111\u00e1p \u00e1n B. <\/span><\/span> ","column":2}]}],"id_ques":737},{"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/bai10/lv1/img\/16.jpg' \/><\/center> Ph\u00e2n t\u00edch \u0111a th\u1ee9c $x^2(x^2+4)+x^2+4$ th\u00e0nh nh\u00e2n t\u1eed \u0111\u01b0\u1ee3c k\u1ebft qu\u1ea3 l\u00e0: ","select":["A. $(x^2+4)(x^2+1)$ ","B. $(x^2+4)(x+1)$","C. $(x^2+4)(x^2-1)$","D. $(x+4)(x^2+1)$"],"hint":" Ph\u00e2n t\u00edch \u0111a th\u1ee9c b\u1eb1ng c\u00e1ch \u0111\u1eb7t nh\u00e2n t\u1eed chung. ","explain":"<span class='basic_left'> Ta c\u00f3: <br\/> $\\begin{align} & {{x}^{2}}({{x}^{2}}+4)+{{x}^{2}}+4 \\\\ & ={{x}^{2}}({{x}^{2}}+4)+\\left( {{x}^{2}}+4 \\right) \\\\ & =\\left( {{x}^{2}}+4 \\right)\\left( {{x}^{2}}+1 \\right) \\\\ \\end{align}$ <br\/> <span class='basic_pink'> V\u1eady ch\u1ecdn \u0111\u00e1p \u00e1n A. <\/span><\/span> ","column":2}]}],"id_ques":738},{"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/bai10/lv1/img\/13.jpg' \/><\/center> \u0110\u1ec3 $(xy+a)(x^2y^2-2xy+4)$ l\u00e0 t\u1ed5ng hai l\u1eadp ph\u01b0\u01a1ng, gi\u00e1 tr\u1ecb c\u1ee7a a l\u00e0: ","select":["A. $1$ ","B. $2$","C. $3$","D. $4$"],"hint":" \u0110\u1eb7t $(xy+a)(x^2y^2-2xy+4)=m^3+n^3=(m+n)(m^2-mn+n^2)$.<br\/> T\u1eeb $x^2y^2-2xy+4=m^2-mn+n^2$ suy ra \u0111\u01b0\u1ee3c $m$ v\u00e0 $n$. T\u1eeb \u0111\u00f3 suy ra gi\u00e1 tr\u1ecb c\u1ee7a $a$. ","explain":"<span class='basic_left'> \u0110\u1eb7t $(xy+a)(x^2y^2-2xy+4)=m^3+n^3$ <br\/> $\\Rightarrow$ $(xy+a)(x^2y^2-2xy+4)=(m+n)(m^2-mn+n^2)$<br\/> Ta c\u00f3: $x^2y^2-2xy+4=(xy)^2-xy.2+2^2=m^2-mn+n^2$<br\/> $ \\Rightarrow \\left\\{ \\begin{aligned} & m=xy \\\\ & n=2 \\\\ \\end{aligned} \\right.\\Rightarrow a=2 $ <br\/> <span class='basic_pink'> V\u1eady ch\u1ecdn \u0111\u00e1p \u00e1n B. <\/span><\/span> ","column":2}]}],"id_ques":739},{"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/bai10/lv1/img\/12.jpg' \/><\/center> \u0110\u1ec3 $\\dfrac{1}{4}+axy+x^2y^2$ l\u00e0 b\u00ecnh ph\u01b0\u01a1ng c\u1ee7a m\u1ed9t hi\u1ec7u, gi\u00e1 tr\u1ecb c\u1ee7a a l\u00e0: ","select":["A. $-1$ ","B. $2$","C. $4$","D. $1$"],"hint":" \u0110\u1eb7t $\\dfrac{1}{4}+axy+x^2y^2=(\\dfrac{1}{2}-xy)^2$, b\u1eb1ng c\u00e1ch \u0111\u1ed3ng nh\u1ea5t h\u1ec7 s\u1ed1 suy ra gi\u00e1 tr\u1ecb c\u1ee7a $a$. ","explain":"<span class='basic_left'>Ta c\u00f3:<br\/> $\\begin{align} & \\dfrac{1}{4}+axy+x^2y^2=(\\dfrac{1}{2}-xy)^2 \\\\ & \\Leftrightarrow \\dfrac{1}{4}+axy+x^2y^2=\\dfrac{1}{4}-xy+x^2y^2 \\\\ & \\Rightarrow axy=-xy \\Leftrightarrow a =-1 \\\\ \\end{align}$ <br\/> <span class='basic_pink'> V\u1eady ch\u1ecdn \u0111\u00e1p \u00e1n A. <\/span><\/span> ","column":2}]}],"id_ques":740},{"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/bai10/lv1/img\/11.jpg' \/><\/center> \u0110\u1ec3 $9x^2+30x+a$ l\u00e0 b\u00ecnh ph\u01b0\u01a1ng c\u1ee7a m\u1ed9t t\u1ed5ng, gi\u00e1 tr\u1ecb c\u1ee7a a l\u00e0: ","select":["A. $9$ ","B. $36$","C. $25$","D. $81$"],"hint":" \u0110\u1eb7t $9x^2+30x+a=(3x+b)^2$, t\u00ecm $b$ b\u1eb1ng c\u00e1ch \u0111\u1ed3ng nh\u1ea5t h\u1ec7 s\u1ed1, t\u1eeb \u0111\u00f3 suy ra gi\u00e1 tr\u1ecb c\u1ee7a $a$. ","explain":"<span class='basic_left'> Ta c\u00f3:<br\/> $\\begin{aligned} & 9{{x}^{2}}+30x+a={{(3x+b)}^{2}} \\\\ & \\Rightarrow 9{{x}^{2}}+30x+a=9{{x}^{2}}+6x.b+{{b}^{2}} \\\\ & \\Rightarrow \\left\\{ \\begin{aligned} & 30x=6x.b \\\\ & a={{b}^{2}} \\\\ \\end{aligned} \\right.\\Rightarrow \\left\\{ \\begin{aligned} & b=5 \\\\ & a={{5}^{2}}=25 \\\\ \\end{aligned} \\right. \\\\ \\end{aligned}$ <br\/> <span class='basic_pink'> V\u1eady ch\u1ecdn \u0111\u00e1p \u00e1n C. <\/span><\/span> ","column":2}]}],"id_ques":741},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 v\u00e0o \u00f4 tr\u1ed1ng ","title_trans":"","temp":"fill_the_blank","correct":[[["1"],["-1"],["3"]]],"list":[{"point":5,"width":40,"type_input":"","ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai10/lv1/img\/10.jpg' \/><\/center> T\u00ecm $x$, bi\u1ebft $3x(x-1)+(x-1)=0$ <br\/> \u0110\u00e1p \u00e1n: $\\left[ \\begin{align} & x=\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{} \\\\ & x=\\dfrac{\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}}{\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}} \\\\ \\end{align} \\right.$ ","hint":" Ph\u00e2n t\u00edch $3x(x-1)+(x-1)$ th\u00e0nh nh\u00e2n t\u1eed b\u1eb1ng c\u00e1ch \u0111\u1eb7t nh\u00e2n t\u1eed chung.<br\/> N\u1ebfu $a.b=0$ th\u00ec $\\left[ \\begin{align} & a=0 \\\\ & b=0 \\\\ \\end{align} \\right.$ ","explain":"<span class='basic_left'> Ta c\u00f3: <br\/> $\\begin{aligned} & 3x(x-1)+(x-1)=0 \\\\ & \\Leftrightarrow (x-1)(3x+1)=0 \\\\ & \\Leftrightarrow \\left[ \\begin{aligned} & x-1=0 \\\\ & 3x+1=0 \\\\ \\end{aligned} \\right.\\Leftrightarrow \\left[ \\begin{aligned} & x=1 \\\\ & x=-\\dfrac{1}{3} \\\\ \\end{aligned} \\right. \\\\ \\end{aligned}$ <br\/> <span class='basic_pink'> Do \u0111\u00f3 ph\u1ea3i \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 1 v\u00e0 $-\\dfrac{1}{3}$. <\/span><\/span> "}]}],"id_ques":742},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 v\u00e0o \u00f4 tr\u1ed1ng ","title_trans":"","temp":"fill_the_blank","correct":[[["-10"]]],"list":[{"point":5,"width":40,"type_input":"","ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai10/lv1/img\/11.jpg' \/><\/center> T\u00ecm $x$, bi\u1ebft $3x+2(5-x)=0$ <br\/> \u0110\u00e1p \u00e1n: $x$ = _input_ ","hint":"","explain":"<span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span> <br\/> Bi\u1ebfn \u0111\u1ed5i, r\u00fat g\u1ecdn \u0111\u01b0a v\u1ec1 d\u1ea1ng $ax + b = 0$ \u0111\u1ec3 t\u00ecm $x$. <br\/> Ta c\u00f3: <br\/> $\\begin{align} & 3x+2(5-x)=0 \\\\ & \\Leftrightarrow 3x+10-2x=0 \\\\ & \\Leftrightarrow x+10=0 \\\\ & \\Rightarrow x=-10 \\\\\\end{align}$ <br\/> <span class='basic_pink'> Do \u0111\u00f3 ph\u1ea3i \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $-10$. <\/span><\/span> "}]}],"id_ques":743},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 v\u00e0o \u00f4 tr\u1ed1ng ","title_trans":"","temp":"fill_the_blank_random","correct":[[["0"],["2"],["-2"]]],"list":[{"point":5,"width":40,"type_input":"","ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai10/lv1/img\/10.jpg' \/><\/center> T\u00ecm $x$, bi\u1ebft $x(x^2-4)=0$ <br\/> \u0110\u00e1p \u00e1n: $\\left[ \\begin{align} & x=\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{} \\\\ & x=\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{} \\\\ & x=\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{} \\\\ \\end{align} \\right.$ ","hint":"","explain":"<span class='basic_left'> Ta c\u00f3: <br\/> $\\begin{aligned} & x({{x}^{2}}-4)=0 \\\\ & \\Leftrightarrow x\\left( x+2 \\right)\\left( x-2 \\right)=0 \\\\ & \\Leftrightarrow \\left[ \\begin{aligned} & x=0 \\\\ & x+2=0 \\\\ & x-2=0 \\\\ \\end{aligned} \\right.\\Leftrightarrow \\left[ \\begin{aligned} & x=0 \\\\ & x=-2 \\\\ & x=2 \\\\ \\end{aligned} \\right. \\\\ \\end{aligned}$ <br\/> <span class='basic_pink'> Do \u0111\u00f3 ph\u1ea3i \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $0, 2; -2$. <\/span><\/span> "}]}],"id_ques":744},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 v\u00e0o \u00f4 tr\u1ed1ng ","title_trans":"","temp":"fill_the_blank","correct":[[["0"]]],"list":[{"point":5,"width":40,"type_input":"","ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai10/lv1/img\/8.jpg' \/><\/center> Gi\u00e1 tr\u1ecb c\u1ee7a bi\u1ec3u th\u1ee9c $x^3+6x^2y+12xy^2+8y^3$ t\u1ea1i $x = - 2; y = 1$ l\u00e0 _input_","hint":"S\u1eed d\u1ee5ng h\u1eb3ng \u0111\u1eb3ng th\u1ee9c l\u1eadp ph\u01b0\u01a1ng c\u1ee7a m\u1ed9t t\u1ed5ng \u0111\u1ec3 r\u00fat g\u1ecdn bi\u1ec3u th\u1ee9c \u0111\u00e3 cho.","explain":"<span class='basic_left'><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 bi\u1ec3u th\u1ee9c<br\/><b>B\u01b0\u1edbc 2:<\/b> Thay $x = -2; y = 1$ v\u00e0 bi\u1ec3u th\u1ee9c <br\/><b>B\u01b0\u1edbc 3:<\/b> T\u00ednh gi\u00e1 tr\u1ecb c\u1ee7a bi\u1ec3u th\u1ee9c<\/span> <br\/><br\/><span class='basic_green'>B\u00e0i gi\u1ea3i<\/span><br\/> Ta c\u00f3: $x^3+6x^2y+12xy^2+8y^3=x^3+3.x^2.2y+3.x.(2y)^2+(2y)^3=(x+2y)^3$<br\/> Thay $x = - 2; y = 1$ v\u00e0o bi\u1ec3u th\u1ee9c $(x+2y)^3$, ta \u0111\u01b0\u1ee3c:<br\/> $(-2+2.1)^3=0$. <br\/> <span class='basic_pink'> Do \u0111\u00f3 ph\u1ea3i \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $0$. <\/span><\/span> "}]}],"id_ques":745},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 v\u00e0o \u00f4 tr\u1ed1ng ","title_trans":"","temp":"fill_the_blank","correct":[[["1000002"]]],"list":[{"point":5,"width":80,"type_input":"","ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai10/lv1/img\/8.jpg' \/><\/center> Gi\u00e1 tr\u1ecb c\u1ee7a bi\u1ec3u th\u1ee9c $a^3-3a^2+3a+1$ t\u1ea1i $a = 101$ l\u00e0 _input_","hint":" S\u1eed d\u1ee5ng ph\u01b0\u01a1ng ph\u00e1p th\u00eam b\u1edbt \u0111\u1ec3 r\u00fat g\u1ecdn bi\u1ec3u th\u1ee9c.","explain":"<span class='basic_left'><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 bi\u1ec3u th\u1ee9c<br\/><b>B\u01b0\u1edbc 2:<\/b> Thay gi\u00e1 tr\u1ecb c\u1ee7a $a$ v\u00e0o bi\u1ec3u th\u1ee9c<br\/><b>B\u01b0\u1edbc 3:<\/b> T\u00ednh gi\u00e1 tr\u1ecb c\u1ee7a bi\u1ec3u th\u1ee9c.<\/span> <br\/><br\/><span class='basic_green'>B\u00e0i gi\u1ea3i<\/span><br\/> Ta c\u00f3: $a^3-3a^2+3a+1=a^3-3a^2+3a-1+1+1=(a-1)^3+2$<br\/> Thay $a = 101$ v\u00e0o bi\u1ec3u th\u1ee9c $(a-1)^3+2$, ta \u0111\u01b0\u1ee3c:<br\/> $(101 - 1)^3 + 2 = 100^3+2=1000002$. <br\/> <span class='basic_pink'> Do \u0111\u00f3 ph\u1ea3i \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $1000002$. <\/span><\/span> "}]}],"id_ques":746},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 v\u00e0o \u00f4 tr\u1ed1ng ","title_trans":"","temp":"fill_the_blank","correct":[[["-25"]]],"list":[{"point":5,"width":40,"type_input":"","ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai10/lv1/img\/5.jpg' \/><\/center> Gi\u00e1 tr\u1ecb c\u1ee7a bi\u1ec3u th\u1ee9c $2x(x+y)+(2x-y)y$ t\u1ea1i $x = 2; y = - 3$ l\u00e0 _input_","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 bi\u1ec3u th\u1ee9c.<br\/> <b> B\u01b0\u1edbc 2:<\/b> Thay $x = 2; y = - 3$ v\u00e0o \u0111\u1ec3 t\u00ednh. <br\/><span class='basic_green'>B\u00e0i gi\u1ea3i<\/span><br\/> Ta c\u00f3: $2x(x+y)+(2x-y)y \\\\ =2x^2+2xy+2xy-y^2 \\\\ = 2x^2+4xy-y^2$<br\/> Thay $x = 2; y = - 3$ v\u00e0o bi\u1ec3u th\u1ee9c $2x^2+4xy-y^2$, ta \u0111\u01b0\u1ee3c:<br\/> $2.2^2+4.2.(-3)-(-3)^2=-25$. <br\/> <span class='basic_pink'> Do \u0111\u00f3 ph\u1ea3i \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $-25$. <\/span><\/span> "}]}],"id_ques":747},{"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/bai10/lv1/img\/4.jpg' \/><\/center> K\u1ebft qu\u1ea3 ph\u00e2n t\u00edch \u0111a th\u1ee9c $16x^2-4y^2$ th\u00e0nh nh\u00e2n t\u1eed l\u00e0: ","select":["A. $4(2x+y)(2x-y)$ ","B. $(2x+y)(2x-y)$","C. $4(4x-y)(4x+y)$","D. $(x+y)^2$"],"hint":" S\u1eed d\u1ee5ng h\u1eb1ng \u0111\u1eb3ng th\u1ee9c $a^2-b^2=(a+b)(a-b)$ ","explain":"<span class='basic_left'><br\/> $\\begin{align} & 16x^2-4y^2 \\\\ & =(4x)^2-(2y)^2 \\\\ & =(4x-2y)(4x+2y) \\\\ & =2(2x-y)2(2x+y) \\\\ & =4(2x+y)(2x-y) \\\\ \\end{align}$ <br\/> <span class='basic_pink'> V\u1eady ch\u1ecdn \u0111\u00e1p \u00e1n A. <\/span><\/span> ","column":2}]}],"id_ques":748},{"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/bai10/lv1/img\/3.jpg' \/><\/center> K\u1ebft qu\u1ea3 r\u00fat g\u1ecdn bi\u1ec3u th\u1ee9c $(x+y)^2-y^2$ l\u00e0: ","select":["A. $x(x+2y)$ ","B. $(x-y)(x+y)$","C. $(x-2y)(x-2xy+4y^2)$","D. $x(x-2y)$"],"hint":" S\u1eed d\u1ee5ng h\u1eb1ng \u0111\u1eb3ng th\u1ee9c: Hi\u1ec7u hai b\u00ecnh ph\u01b0\u01a1ng \u0111\u1ec3 r\u00fat g\u1ecdn bi\u1ec3u th\u1ee9c. ","explain":"<span class='basic_left'><br\/>$\\begin{align} & (x+y)^2-y^2 \\\\ & = (x+y+y)(x+y-y) \\\\ & =(x+2y)x \\\\ \\end{align}$ <br\/> <span class='basic_pink'> V\u1eady ch\u1ecdn \u0111\u00e1p \u00e1n A. <\/span><\/span> ","column":2}]}],"id_ques":749},{"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/bai10/lv1/img\/2.jpg' \/><\/center> K\u1ebft qu\u1ea3 ph\u00e9p nh\u00e2n \u0111a th\u1ee9c v\u1edbi \u0111\u01a1n th\u1ee9c $(2xy-x^2+2y).\\dfrac{1}{2}xy^2$ l\u00e0: ","select":["A. $x^2y^3-\\dfrac{1}{2}x^3y^2+xy^3$ ","B. $xy^2-\\dfrac{1}{2}x^2y^2+xy^3$","C. $x^2y^3+\\dfrac{1}{2}x^3y^2+x^2y^2$","D. $2x^2y^3-\\dfrac{1}{2}x^2y^2+xy^3$"],"hint":" Nh\u00e2n \u0111a th\u1ee9c v\u1edbi \u0111\u01a1n th\u1ee9c: ta nh\u00e2n t\u1eebng h\u1ea1ng t\u1eed c\u1ee7a \u0111a th\u1ee9c \u0111\u00f3 v\u1edbi \u0111\u01a1n th\u1ee9c r\u1ed3i c\u1ed9ng c\u00e1c t\u00edch v\u1edbi nhau.","explain":"<span class='basic_left'><br\/>Ta c\u00f3:<br\/> $(2xy-{{x}^{2}}+2y).\\dfrac{1}{2}x{{y}^{2}}={{x}^{2}}{{y}^{3}}-\\dfrac{1}{2}{{x}^{3}}{{y}^{2}}+x{{y}^{3}}$ <br\/> <span class='basic_pink'> V\u1eady ch\u1ecdn \u0111\u00e1p \u00e1n A. <\/span><\/span> ","column":2}]}],"id_ques":750}],"lesson":{"save":0,"level":1}}