{"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\u1ebft $\\left( 3x+4 \\right)\\left( x-2 \\right)-\\left( x-2 \\right)=0$, gi\u00e1 tr\u1ecb c\u1ee7a $x$ l\u00e0:","select":["A. $\\left[ \\begin{align} & x=2 \\\\ & x=-1 \\\\ \\end{align} \\right.$","B. $\\left[ \\begin{align} & x=3 \\\\ & x= 1 \\\\ \\end{align} \\right.$","C. $\\left[ \\begin{align} & x=3 \\\\ & x=-\\dfrac{4}{3} \\\\ \\end{align} \\right.$","D. $\\left[ \\begin{align} & x=3 \\\\ & x=\\dfrac{4}{3} \\\\ \\end{align} \\right.$"],"hint":"Bi\u1ebfn \u0111\u1ed5i \u0111\u1eb3ng th\u1ee9c \u0111\u00e3 cho \u0111\u1ec3 t\u00ecm $x$.<br\/>N\u1ebfu $a.b = 0$ th\u00ec ho\u1eb7c $a = 0$ ho\u1eb7c $b = 0$.","explain":"<span class='basic_left'>Ta c\u00f3:<br\/> $\\begin{aligned}& \\left( 3x+4 \\right)\\left( x-2 \\right)-\\left( x-2 \\right)=0 \\\\ & \\Leftrightarrow \\left( x-2 \\right)\\left( 3x+4-1 \\right)=0 \\\\ & \\Leftrightarrow \\left( x-2 \\right)\\left( 3x+3 \\right)=0 \\\\ & \\Leftrightarrow \\left[ \\begin{aligned}& x-2=0 \\\\ & 3x+3=0 \\\\ \\end{aligned} \\right.\\Leftrightarrow \\left[ \\begin{aligned}& x=2 \\\\ & x=-1 \\\\ \\end{aligned} \\right. \\\\ \\end{aligned}$ <br\/><span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 A.<\/span>","column":2}]}],"id_ques":351},{"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":[[["1"],["6"]]],"list":[{"point":5,"width":40,"content":"","type_input":"","ques":"T\u00ecm $x$, bi\u1ebft: $\\left( x-5 \\right)\\left( x-1 \\right)=x-1$.<br\/>Gi\u00e1 tr\u1ecb c\u1ee7a $x$ c\u1ea7n t\u00ecm l\u00e0 $\\left[ \\begin{align}& x= \\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}\\\\ & x= \\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}\\\\ \\end{align} \\right.$ ","hint":"Chuy\u1ec3n v\u1ebf v\u00e0 \u0111\u1eb7t nh\u00e2n t\u1eed chung \u0111\u01b0a v\u1ec1 d\u1ea1ng $a.b=0$ <br\/>N\u1ebfu $a.b = 0$ th\u00ec ho\u1eb7c $a = 0$ ho\u1eb7c $b = 0$.","explain":"<span class='basic_left'>Ta c\u00f3:<br\/>$\\begin{aligned}& \\left( x-5 \\right)\\left( x-1 \\right)=x-1 \\\\ & \\Leftrightarrow \\left( x-5 \\right)\\left( x-1 \\right)-\\left( x-1 \\right)=0 \\\\ & \\Leftrightarrow \\left( x-1 \\right)\\left( x-5-1 \\right)=0 \\\\ & \\Leftrightarrow \\left( x-1 \\right)\\left( x-6 \\right)=0 \\\\ & \\Leftrightarrow \\left[ \\begin{aligned} & x-1=0 \\\\ & x-6=0 \\\\ \\end{aligned} \\right.\\Leftrightarrow \\left[ \\begin{aligned}& x=1 \\\\ & x=6 \\\\ \\end{aligned} \\right. \\\\ \\end{aligned}$<br\/> <span class='basic_pink'> V\u1eady gi\u00e1 tr\u1ecb $x$ c\u1ea7n \u0111i\u1ec1n l\u00e0 $1$ ho\u1eb7c $6$.<\/span>"}]}],"id_ques":352},{"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/bai2/lv2/img\/1.png' \/><\/center>Bi\u1ec3u th\u1ee9c $\\left( a-1 \\right)\\left( a+2 \\right)\\left( a+3 \\right)$ l\u00e0 \u0111a th\u1ee9c b\u1eadc $5$. \u0110\u00fang hay sai? ","select":["\u0110\u00fang","Sai"],"hint":"<br\/>Ta nh\u00e2n \u0111a th\u1ee9c v\u1edbi \u0111a th\u1ee9c, s\u1eed d\u1ee5ng c\u00f4ng th\u1ee9c: $(a+b)(c+d)=ac+ad+bc+bd$<br\/> Sau \u0111\u00f3 t\u00ecm b\u1eadc c\u1ee7a \u0111a th\u1ee9c thu \u0111\u01b0\u1ee3c.","explain":"<span class='basic_left'>Ta c\u00f3:<br\/>$\\begin{align}& \\left( a-1 \\right)\\left( a+2 \\right)\\left( a+3 \\right) \\\\ & =\\left( {{a}^{2}}+2a-a-2 \\right)\\left( a+3 \\right) \\\\ & =\\left( {{a}^{2}}+a-2 \\right)\\left( a+3 \\right) \\\\ & ={{a}^{3}}+3{{a}^{2}}+{{a}^{2}}+3a-2a-6 \\\\ & ={{a}^{3}}+4{{a}^{2}}+a-6 \\\\ \\end{align}$<br\/>\u0110a th\u1ee9c thu \u0111\u01b0\u1ee3c c\u00f3 b\u1eadc l\u00e0 $3$<span><br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 Sai.<\/span>","column":2}]}],"id_ques":353},{"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/bai2/lv2/img\/1.png' \/><\/center>Bi\u1ec3u th\u1ee9c $\\left( -\\dfrac{2}{3}x+3 \\right)\\left( 3{{x}^{2}}-4x+6 \\right)$ l\u00e0 \u0111a th\u1ee9c b\u1eadc $3$. \u0110\u00fang hay sai? ","select":["\u0110\u00fang","Sai"],"hint":"<br\/>Ta nh\u00e2n \u0111a th\u1ee9c v\u1edbi \u0111a th\u1ee9c, s\u1eed d\u1ee5ng c\u00f4ng th\u1ee9c: $(a+b)(c+d)=ac+ad+bc+bd$<br\/> Sau \u0111\u00f3 t\u00ecm b\u1eadc c\u1ee7a \u0111a th\u1ee9c thu \u0111\u01b0\u1ee3c.","explain":"<span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn<\/span><br\/> <b>B\u01b0\u1edbc 1:<\/b> Ta nh\u00e2n \u0111a th\u1ee9c v\u1edbi \u0111a th\u1ee9c, s\u1eed d\u1ee5ng c\u00f4ng th\u1ee9c: $(a+b)(c+d)=ac+ad+bc+bd$ <br\/> <b>B\u01b0\u1edbc 2:<\/b> S\u1eafp x\u1ebfp k\u1ebft qu\u1ea3 theo l\u0169y th\u1eeba gi\u1ea3m d\u1ea7n v\u00e0 sau \u0111\u00f3 t\u00ecm b\u1eadc c\u1ee7a \u0111a th\u1ee9c thu \u0111\u01b0\u1ee3c.<br\/><span class='basic_green'>Gi\u1ea3i<\/span><br\/><span class='basic_left'>Ta c\u00f3:<br\/>$ \\left( -\\dfrac{2}{3}x+3 \\right)\\left( 3{{x}^{2}}-4x+6 \\right) $<br\/>$ =-2{{x}^{3}}+\\dfrac{8}{3}{{x}^{2}}-4x+9{{x}^{2}}-12x+18 $<br\/>$ =-2{{x}^{3}}+\\dfrac{35}{3}{{x}^{2}}-16x+18 $<br\/>\u0110a th\u1ee9c thu \u0111\u01b0\u1ee3c c\u00f3 b\u1eadc l\u00e0 $3$<span><br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 \u0110\u00fang.<\/span>","column":2}]}],"id_ques":354},{"time":24,"part":[{"title":"\u0110i\u1ec1n v\u00e0o ch\u1ed7 tr\u1ed1ng ","title_trans":"","temp":"fill_the_blank","correct":[[["1"],["3"]]],"list":[{"point":5,"width":40,"type_input":"","ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai2/lv2/img\/1.png' \/><\/center>H\u1ec7 s\u1ed1 cao nh\u1ea5t c\u1ee7a k\u1ebft qu\u1ea3 ph\u00e9p nh\u00e2n $\\left( {{m}^{2}}-\\dfrac{1}{3}{{m}^{5}} \\right)\\left( m+1 \\right)$ l\u00e0 -$\\dfrac{\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}}{\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}}$","hint":"Trong \u0111a th\u1ee9c m\u1ed9t bi\u1ebfn: h\u1ec7 s\u1ed1 cao nh\u1ea5t l\u00e0 h\u1ec7 s\u1ed1 \u0111i v\u1edbi bi\u1ebfn c\u00f3 l\u0169y th\u1eeba cao nh\u1ea5t.","explain":"<span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn<\/span><br\/> <b>B\u01b0\u1edbc 1:<\/b> Nh\u00e2n t\u1eebng h\u1ea1ng t\u1eed c\u1ee7a \u0111a th\u1ee9c n\u00e0y v\u1edbi t\u1eebng h\u1ea1ng t\u1eed c\u1ee7a \u0111a th\u1ee9c kia: $(a+b)(c+d) = ac+ad+bc+bd$<br\/> <b>B\u01b0\u1edbc 2:<\/b> S\u1eafp x\u1ebfp \u0111a th\u1ee9c theo l\u0169y th\u1eeba gi\u1ea3m d\u1ea7n v\u00e0 t\u00ecm b\u1eadc c\u1ee7a \u0111a th\u1ee9c \u0111\u00f3.<br\/><span class='basic_green'>Gi\u1ea3i<\/span><br\/>Ta nh\u00e2n:<br\/>$\\begin{align}& \\left( {{m}^{2}}-\\dfrac{1}{3}{{m}^{5}} \\right)\\left( m+1 \\right) \\\\ & ={{m}^{3}}+{{m}^{2}}-\\dfrac{1}{3}{{m}^{6}}-\\dfrac{1}{3}{{m}^{5}} \\\\ & =-\\dfrac{1}{3}{{m}^{6}}-\\dfrac{1}{3}{{m}^{5}}+{{m}^{3}}+{{m}^{2}} \\\\ \\end{align}$<br\/> \u0110a th\u1ee9c c\u00f3 l\u0169y th\u1eeba cao nh\u1ea5t c\u1ee7a bi\u1ebfn l\u00e0 $6$.<br\/> Do \u0111\u00f3 h\u1ec7 s\u1ed1 cao nh\u1ea5t l\u00e0 $\\dfrac{-1}{3}$ (hay -$\\dfrac{1}{3}$).<br\/><span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n c\u1ea7n \u0111i\u1ec1n l\u00e0 $\\dfrac{1}{3}$.<\/span><\/span>"}]}],"id_ques":355},{"time":24,"part":[{"title":"\u0110i\u1ec1n v\u00e0o ch\u1ed7 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/bai2/lv2/img\/1.png' \/><\/center>H\u1ec7 s\u1ed1 cao nh\u1ea5t c\u1ee7a k\u1ebft qu\u1ea3 ph\u00e9p nh\u00e2n $\\left( {{x}^{4}}-3x+\\dfrac{5}{6} \\right)\\left( {{x}^{3}}+x-1 \\right)$ l\u00e0 _input_","hint":"Trong \u0111a th\u1ee9c m\u1ed9t bi\u1ebfn: h\u1ec7 s\u1ed1 cao nh\u1ea5t l\u00e0 h\u1ec7 s\u1ed1 \u0111i v\u1edbi bi\u1ebfn c\u00f3 l\u0169y th\u1eeba cao nh\u1ea5t.","explain":"<span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn<\/span><br\/> <b>B\u01b0\u1edbc 1:<\/b> Nh\u00e2n t\u1eebng h\u1ea1ng t\u1eed c\u1ee7a \u0111a th\u1ee9c n\u00e0y v\u1edbi t\u1eebng h\u1ea1ng t\u1eed c\u1ee7a \u0111a th\u1ee9c kia: $(a+b)(c+d) = ac+ad+bc+bd$<br\/> <b>B\u01b0\u1edbc 2:<\/b> S\u1eafp x\u1ebfp \u0111a th\u1ee9c theo l\u0169y th\u1eeba gi\u1ea3m d\u1ea7n v\u00e0 t\u00ecm b\u1eadc c\u1ee7a \u0111a th\u1ee9c \u0111\u00f3.<br\/><span class='basic_green'>Gi\u1ea3i<\/span><br\/>Ta c\u00f3:<br\/>$ \\left( {{x}^{4}}-3x+\\dfrac{5}{6} \\right)\\left( {{x}^{3}}+x-1 \\right) $<br\/>$ ={{x}^{7}}+{{x}^{5}}-{{x}^{4}}-3{{x}^{4}}-3{{x}^{2}}$$+3x+\\dfrac{5}{6}{{x}^{3}}+\\dfrac{5}{6}x-\\dfrac{5}{6} $<br\/>$ ={{x}^{7}}+{{x}^{5}}-4{{x}^{4}}+\\dfrac{5}{6}{{x}^{3}}-3{{x}^{2}}$$+\\dfrac{23}{6}x-\\dfrac{5}{6} $<br\/> \u0110a th\u1ee9c c\u00f3 l\u0169y th\u1eeba cao nh\u1ea5t c\u1ee7a bi\u1ebfn l\u00e0 $7$.<br\/> Do \u0111\u00f3 h\u1ec7 s\u1ed1 cao nh\u1ea5t l\u00e0 $1$.<br\/><span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n c\u1ea7n \u0111i\u1ec1n l\u00e0 $1$.<\/span><\/span> "}]}],"id_ques":356},{"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/bai2/lv2/img\/1.png' \/><\/center>Gi\u00e1 tr\u1ecb c\u1ee7a bi\u1ec3u th\u1ee9c $\\left( 4{{m}^{2}}-3n \\right)\\left( 3m-2n \\right)$ t\u1ea1i $m = 1; n= 2$ l\u00e0: ","select":["A. 1","B. 5","C. 7","D. 2"],"hint":"Thay gi\u00e1 tr\u1ecb c\u1ee7a $m$ v\u00e0 $n$ v\u00e0o bi\u1ec3u th\u1ee9c \u0111\u00e3 cho \u0111\u1ec3 t\u00ednh.","explain":"<span class='basic_left'>Thay $m = 1; n = 2$ v\u00e0o bi\u1ec3u th\u1ee9c $\\left( 4{{m}^{2}}-3n \\right)\\left( 3m-2n \\right)$, ta \u0111\u01b0\u1ee3c:<br\/> $\\left( 4.1^2-3.2 \\right)\\left( 3.1-2.2 \\right)=\\left( -2 \\right).\\left( -1 \\right)=2$<br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 D.<\/span><\/span><\/span>","column":2}]}],"id_ques":357},{"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/bai2/lv2/img\/1.png' \/><\/center>Gi\u00e1 tr\u1ecb c\u1ee7a bi\u1ec3u th\u1ee9c $\\left( 2-2x{{y}^{2}} \\right)\\left( \\dfrac{1}{5}-x+y \\right)$ t\u1ea1i $x = 1; y = 2$ l\u00e0: ","select":["A. $-\\dfrac{26}{5}$","B. $-\\dfrac{36}{5}$","C. $-\\dfrac{24}{5}$","D. $-\\dfrac{2}{5}$"],"hint":"Thay gi\u00e1 tr\u1ecb c\u1ee7a $x$ v\u00e0 $y$ v\u00e0o bi\u1ec3u th\u1ee9c \u0111\u00e3 cho \u0111\u1ec3 t\u00ednh.","explain":"<span class='basic_left'>Thay $x = 1; y = 2$ v\u00e0o bi\u1ec3u th\u1ee9c \u0111\u00e3 cho, ta \u0111\u01b0\u1ee3c:<br\/> $\\left( 2-2x{{y}^{2}} \\right)\\left( \\dfrac{1}{5}-x+y \\right)=\\left( 2-{{2.1.2}^{2}} \\right)\\left( \\dfrac{1}{5}-1+2 \\right)= -6 .\\left( \\dfrac{6}{5} \\right)=\\dfrac{-36}{5}$<br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span>","column":2}]}],"id_ques":358},{"time":24,"part":[{"title":"\u0110i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng ","title_trans":"","temp":"fill_the_blank","correct":[[["1"],["4"]]],"list":[{"point":5,"width":40,"type_input":"","ques":"Gi\u00e1 tr\u1ecb c\u1ee7a bi\u1ec3u th\u1ee9c $\\left( xy-y+\\dfrac{1}{2} \\right)\\left( -2y+\\dfrac{1}{2} \\right)$ t\u1ea1i $x = 2; y = 0$ l\u00e0 $\\dfrac{\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}}{\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}}$","hint":"Thay gi\u00e1 tr\u1ecb $x, y$ v\u00e0o \u0111a th\u1ee9c \u0111\u00e3 cho \u0111\u1ec3 t\u00ednh.","explain":"<span class='basic_left'>Ta thay $x = 2; y = 0$ v\u00e0o bi\u1ec3u th\u1ee9c \u0111\u00e3 cho:<br\/> $\\left( xy-y+\\dfrac{1}{2} \\right)\\left( -2y+\\dfrac{1}{2} \\right)=\\left( 2.0-0+\\dfrac{1}{2} \\right)\\left( -2.0+\\dfrac{1}{2} \\right)$$=\\dfrac{1}{2}.\\dfrac{1}{2}=\\dfrac{1}{4}$<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n c\u1ea7n \u0111i\u1ec1n l\u00e0 $\\dfrac{1}{4}$.<\/span> "}]}],"id_ques":359},{"time":24,"part":[{"title":"\u0110i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng ","title_trans":"","temp":"fill_the_blank","correct":[[["4"]]],"list":[{"point":5,"width":40,"type_input":"","ques":"Gi\u00e1 tr\u1ecb c\u1ee7a bi\u1ec3u th\u1ee9c $\\left( 2{{x}^{3}}y+1 \\right)\\left( \\dfrac{3}{2}x+1 \\right)$ t\u1ea1i $x = 2; y = 0$ l\u00e0 _input_","hint":"Thay gi\u00e1 tr\u1ecb $x, y$ v\u00e0o \u0111a th\u1ee9c \u0111\u00e3 cho \u0111\u1ec3 t\u00ednh.","explain":"<span class='basic_left'>Ta thay $x = 2; y = 0$ v\u00e0o bi\u1ec3u th\u1ee9c \u0111\u00e3 cho:<br\/> $\\left( 2{{x}^{3}}y+1 \\right)\\left( \\dfrac{3}{2}x+1 \\right)=\\left( {{2.2}^{3}}.0+1 \\right)\\left( \\dfrac{3}{2}.2+1 \\right)=4$<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n c\u1ea7n \u0111i\u1ec1n l\u00e0 $4$.<\/span> "}]}],"id_ques":360},{"time":24,"part":[{"title":"\u0110i\u1ec1n d\u1ea5u + ho\u1eb7c - v\u00e0o \u00f4 tr\u1ed1ng \u0111\u1ec3 \u0111\u01b0\u1ee3c khai tri\u1ec3n \u0111\u00fang","title_trans":"","temp":"fill_the_blank_random","correct":[[["+"],["+"]]],"list":[{"point":5,"width":40,"type_input":"","ques":"$\\left( 3a+2b \\right)\\left( 4a+3b \\right)$$=12{{a}^{2}}\\,\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}\\,\\, 17ab\\,\\,\\,\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}\\,6{{b}^{2}}$","hint":"Nh\u00e2n t\u1eebng h\u1ea1ng t\u1eed c\u1ee7a \u0111a th\u1ee9c n\u00e0y v\u1edbi t\u1eebng h\u1ea1ng t\u1eed c\u1ee7a \u0111a th\u1ee9c kia: $(a+b)(c+d) = ac+ad+bc+bd$, t\u1eeb \u0111\u00f3 t\u00ecm ra d\u1ea5u + ho\u1eb7c - c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng.","explain":"<span class='basic_left'>Ta c\u00f3:<br\/> $\\left( 3a+2b \\right)\\left( 4a+3b \\right)=12{{a}^{2}}\\,+\\,\\,17ab\\,\\,+\\,\\,6{{b}^{2}}$<span><br\/> <span class='basic_pink'> V\u1eady c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng d\u1ea5u $+$ v\u00e0 $+$.<\/span>"}]}],"id_ques":361},{"time":24,"part":[{"title":"\u0110i\u1ec1n d\u1ea5u + ho\u1eb7c - v\u00e0o \u00f4 tr\u1ed1ng \u0111\u1ec3 \u0111\u01b0\u1ee3c khai tri\u1ec3n \u0111\u00fang","title_trans":"","temp":"fill_the_blank_random","correct":[[["-"],["-"]]],"list":[{"point":5,"width":40,"type_input":"","ques":"$\\left( {{x}^{2}}-y \\right)\\left( {{y}^{2}}-z \\right)$$={{x}^{2}}{{y}^{2}}\\,\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}\\,{{x}^{2}}z\\,\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}\\,{{y}^{3}}+yz$","hint":"Nh\u00e2n t\u1eebng h\u1ea1ng t\u1eed c\u1ee7a \u0111a th\u1ee9c n\u00e0y v\u1edbi t\u1eebng h\u1ea1ng t\u1eed c\u1ee7a \u0111a th\u1ee9c kia: $(a+b)(c+d) = ac+ad+bc+bd$, t\u1eeb \u0111\u00f3 t\u00ecm ra d\u1ea5u + ho\u1eb7c - c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng.","explain":"<span class='basic_left'>Ta th\u1ef1c hi\u1ec7n ph\u00e9p nh\u00e2n:<br\/> $\\left( {{x}^{2}}-y \\right)\\left( {{y}^{2}}-z \\right)={{x}^{2}}{{y}^{2}}\\,-{{x}^{2}}z\\,\\,-{{y}^{3}}+yz$<span><br\/> <span class='basic_pink'> V\u1eady c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng d\u1ea5u $-$ v\u00e0 $-$.<\/span>"}]}],"id_ques":362},{"time":24,"part":[{"title":"\u0110i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng \u0111\u1ec3 \u0111\u01b0\u1ee3c khai tri\u1ec3n \u0111\u00fang","title_trans":"","temp":"fill_the_blank_random","correct":[[["4"],["4"]]],"list":[{"point":5,"width":40,"type_input":"","ques":"$\\left( x-4 \\right)\\left( {{x}^{2}}+4 \\right)$$={{x}^{3}}-\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}{{x}^{2}}$$+\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}x-16$","hint":"Nh\u00e2n t\u1eebng h\u1ea1ng t\u1eed c\u1ee7a \u0111a th\u1ee9c n\u00e0y v\u1edbi t\u1eebng h\u1ea1ng t\u1eed c\u1ee7a \u0111a th\u1ee9c kia: $(a+b)(c+d) = ac+ad+bc+bd$, t\u1eeb \u0111\u00f3 t\u00ecm ra y\u1ebfu t\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng.","explain":"<span class='basic_left'>Ta th\u1ef1c hi\u1ec7n ph\u00e9p nh\u00e2n:<br\/> $\\left( x-4 \\right)\\left( {{x}^{2}}+4 \\right)={{x}^{3}}-4{{x}^{2}}+4x-16$<span><br\/> <span class='basic_pink'> V\u1eady c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $4$ v\u00e0 $4$.<\/span>"}]}],"id_ques":363},{"time":24,"part":[{"title":"\u0110i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng \u0111\u1ec3 \u0111\u01b0\u1ee3c khai tri\u1ec3n \u0111\u00fang","title_trans":"","temp":"fill_the_blank_random","correct":[[["a"],["b"]]],"list":[{"point":5,"width":40,"type_input":"","ques":"$\\left( x+a \\right)\\left( x+b \\right)$$={{x}^{2}}+\\left(\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}+\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{} \\right)x$$+ab$","hint":"Nh\u00e2n t\u1eebng h\u1ea1ng t\u1eed c\u1ee7a \u0111a th\u1ee9c n\u00e0y v\u1edbi t\u1eebng h\u1ea1ng t\u1eed c\u1ee7a \u0111a th\u1ee9c kia: $(a+b)(c+d) = ac+ad+bc+bd$, t\u1eeb \u0111\u00f3 t\u00ecm ra y\u1ebfu t\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng.","explain":"<span class='basic_left'>Ta th\u1ef1c hi\u1ec7n ph\u00e9p nh\u00e2n:<br\/> $\\left( x+a \\right)\\left( x+b \\right)={{x}^{2}}+\\left( a+b \\right)x+ab$<span><br\/> <span class='basic_pink'> V\u1eady c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $a$ v\u00e0 $b$.<\/span>"}]}],"id_ques":364},{"time":24,"part":[{"title":"\u0110i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng ","title_trans":"","temp":"fill_the_blank","correct":[[["-1"]]],"list":[{"point":5,"width":40,"type_input":"","ques":"H\u1ec7 s\u1ed1 c\u1ee7a $y^3$ trong \u0111a th\u1ee9c $\\left( \\dfrac{4}{3}y-\\dfrac{1}{3} \\right)\\left( {3{y}^{3}}-5 \\right)$ l\u00e0 _input_","hint":"Ta \u0111i r\u00fat g\u1ecdn \u0111a th\u1ee9c \u0111\u00e3 cho, \u00e1p d\u1ee5ng: $(a+b)(c+d) = ac+ad+bc+bd$<br\/> T\u00ecm h\u1ec7 s\u1ed1 \u0111i v\u1edbi \u1ea9n $y^5$.","explain":"<span class='basic_left'>Ta c\u00f3:<br\/>$\\begin{align} & \\left( \\frac{4}{3}y-\\dfrac{1}{3} \\right)\\left( {3{y}^{3}}-5 \\right) \\\\ & =4{{y}^{4}}-\\dfrac{20}{3}y-{{y}^{3}}+\\dfrac{5}{3} \\\\ & =4{{y}^{4}}-{{y}^{3}}-\\dfrac{20}{3}y+\\dfrac{5}{3} \\\\ \\end{align}$<br\/> H\u1ec7 s\u1ed1 \u0111i v\u1edbi \u1ea9n $y^3$ l\u00e0 $-1$. <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n c\u1ea7n \u0111i\u1ec1n l\u00e0 $-1$.<\/span><\/span> "}]}],"id_ques":365},{"time":24,"part":[{"title":"\u0110i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng ","title_trans":"","temp":"fill_the_blank","correct":[[["5"]]],"list":[{"point":5,"width":40,"type_input":"","ques":"H\u1ec7 s\u1ed1 c\u1ee7a $x^7$ trong \u0111a th\u1ee9c $\\left( {{x}^{4}}-3x-2 \\right)\\left( 5{{x}^{3}}-8 \\right)$ l\u00e0 _input_","hint":"Ta \u0111i r\u00fat g\u1ecdn \u0111a th\u1ee9c \u0111\u00e3 cho, \u00e1p d\u1ee5ng: $(a+b)(c+d) = ac+ad+bc+bd$<br\/> T\u00ecm h\u1ec7 s\u1ed1 \u0111i v\u1edbi \u1ea9n $x^7$","explain":"<span class='basic_left'>Ta c\u00f3:<br\/> $\\left( {{x}^{4}}-3x-2 \\right)\\left( 5{{x}^{3}}-8 \\right) $<br\/>$ =5{{x}^{7}}-8{{x}^{4}}-15{{x}^{4}}+24x-10{{x}^{3}}+16 $<br\/>$ =5{{x}^{7}}-23{{x}^{4}}-10{{x}^{3}}+24x+16 $<br\/> H\u1ec7 s\u1ed1 \u0111i v\u1edbi \u1ea9n $x^7$ l\u00e0 $5$. <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n c\u1ea7n \u0111i\u1ec1n l\u00e0 $5$.<\/span><\/span> "}]}],"id_ques":366},{"time":24,"part":[{"title":"\u0110i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng ","title_trans":"","temp":"fill_the_blank","correct":[[["1"]]],"list":[{"point":5,"width":40,"type_input":"","ques":"H\u1ec7 s\u1ed1 c\u1ee7a $x^4$ trong \u0111a th\u1ee9c $\\left( {{x}^{3}}-2{{x}^{2}}+x-1 \\right)\\left( x-9 \\right)$ l\u00e0 _input_","hint":"R\u00fat g\u1ecdn \u0111a th\u1ee9c \u0111\u00e3 cho, \u00e1p d\u1ee5ng: $(a+b)(c+d) = ac+ad+bc+bd$<br\/> T\u00ecm h\u1ec7 s\u1ed1 \u0111i v\u1edbi \u1ea9n $x^4$","explain":"<span class='basic_left'>Ta c\u00f3:<br\/> $ \\left( {{x}^{3}}-2{{x}^{2}}+x-1 \\right)\\left( x-9 \\right) $<br\/>$ ={{x}^{4}}-9{{x}^{3}}-2{{x}^{3}}+18{{x}^{2}}+{{x}^{2}}-9x-x+9 $<br\/>$ ={{x}^{4}}-11{{x}^{3}}+19{{x}^{2}}-10x+9 $<br\/> H\u1ec7 s\u1ed1 \u0111i v\u1edbi \u1ea9n $x^4$ l\u00e0 $1$. <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n c\u1ea7n \u0111i\u1ec1n l\u00e0 $1$.<\/span><\/span> "}]}],"id_ques":367},{"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/bai2/lv2/img\/1.png' \/><\/center>K\u1ebft qu\u1ea3 ph\u00e9p nh\u00e2n $\\left( {{x}^{2}}-2x-1 \\right)\\left( x-1 \\right)$ l\u00e0:","select":["A. $-{{x}^{3}}-3{{x}^{2}}-3x$ ","B. ${{x}^{3}}+3{{x}^{2}}-3x+1$ ","C. ${{x}^{3}}-3{{x}^{2}}+x+1$","D. ${{x}^{3}}-3{{x}^{2}}-3x+1$"],"hint":"Nh\u00e2n t\u1eebng h\u1ea1ng t\u1eed c\u1ee7a \u0111a th\u1ee9c n\u00e0y v\u1edbi t\u1eebng h\u1ea1ng t\u1eed c\u1ee7a \u0111a th\u1ee9c kia: $(a+b)(c+d) = ac+ad+bc+bd$","explain":"<span class='basic_left'>Ta th\u1ef1c hi\u1ec7n ph\u00e9p nh\u00e2n:<br\/> $\\begin{align} & \\left( {{x}^{2}}-2x-1 \\right)\\left( x-1 \\right) \\\\ & ={{x}^{3}}-{{x}^{2}}-2{{x}^{2}}+2x-x+1 \\\\ & ={{x}^{3}}-3{{x}^{2}}+x+1 \\\\ \\end{align}$<span><br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 C.<\/span>","column":2}]}],"id_ques":368},{"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/bai2/lv2/img\/1.png' \/><\/center>K\u1ebft qu\u1ea3 ph\u00e9p nh\u00e2n $\\left( x+0,5 \\right)\\left( {{x}^{2}}+2x-0,5 \\right)$ l\u00e0:","select":["A. ${{x}^{3}}-2,5{{x}^{2}}+0,5x-0,25$ ","B. ${{x}^{3}}+2,5{{x}^{2}}+0,5x-0,25$ ","C. ${{x}^{3}}-2,5{{x}^{2}}-0,5x+0,25$","D. ${{x}^{3}}+2,5{{x}^{2}}-0,5x-0,25$"],"hint":"Nh\u00e2n t\u1eebng h\u1ea1ng t\u1eed c\u1ee7a \u0111a th\u1ee9c n\u00e0y v\u1edbi t\u1eebng h\u1ea1ng t\u1eed c\u1ee7a \u0111a th\u1ee9c kia: $(a+b)(c+d) = ac+ad+bc+bd$","explain":"<span class='basic_left'>Ta th\u1ef1c hi\u1ec7n ph\u00e9p nh\u00e2n:<br\/> $ \\left( x+0,5 \\right)\\left( {{x}^{2}}+2x-0,5 \\right) $<br\/>$ ={{x}^{3}}+2{{x}^{2}}-0,5x+0,5{{x}^{2}}+x-0,25 $<br\/>$={{x}^{3}}+2,5{{x}^{2}}+0,5x-0,25 $<span><br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 B.<\/span>","column":2}]}],"id_ques":369},{"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/bai2/lv2/img\/1.png' \/><\/center>K\u1ebft qu\u1ea3 ph\u00e9p nh\u00e2n $\\left( 0,2-\\dfrac{1}{3}x \\right)\\left( 0,2+\\dfrac{1}{3}x \\right)$ l\u00e0:","select":["A. $0,04-\\dfrac{1}{9}{{x}^{2}}$ ","B. $0,04+\\dfrac{1}{9}{{x}^{2}}$ ","C. $0,04-\\dfrac{1}{3}{{x}^{2}}$","D. $0,4-\\dfrac{1}{9}{{x}^{2}}$"],"hint":"Nh\u00e2n t\u1eebng h\u1ea1ng t\u1eed c\u1ee7a \u0111a th\u1ee9c n\u00e0y v\u1edbi t\u1eebng h\u1ea1ng t\u1eed c\u1ee7a \u0111a th\u1ee9c kia: $(a+b)(c+d) = ac+ad+bc+bd$","explain":"<span class='basic_left'>Ta th\u1ef1c hi\u1ec7n ph\u00e9p nh\u00e2n:<br\/> $\\begin{align}& \\left( 0,2-\\dfrac{1}{3}x \\right)\\left( 0,2+\\dfrac{1}{3}x \\right) \\\\ & =0,04+\\dfrac{1}{15}x-\\dfrac{1}{15}x-\\dfrac{1}{9}{{x}^{2}} \\\\ & =-\\dfrac{1}{9}{{x}^{2}}+0,04 \\\\ \\end{align}$<span><br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 A.<\/span>","column":2}]}],"id_ques":370}],"lesson":{"save":0,"level":2}}