{"segment":[{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00fang hay sai","title_trans":"","temp":"true_false","correct":[["f","t"]],"list":[{"point":5,"image":"https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai12/lv2/img\/5.jpg","col_name":["Kh\u1eb3ng \u0111\u1ecbnh","\u0110\u00fang","Sai"],"arr_ques":["Ph\u00e2n th\u1ee9c $\\dfrac{1}{100x^2-20x^3}$ c\u00f3 ngh\u0129a khi $x\\,\\ne 0;x\\ne \\dfrac{1}{5}$ ","K\u1ebft qu\u1ea3 r\u00fat g\u1ecdn ph\u00e2n th\u1ee9c $\\dfrac{135x-45x^2}{15x(x-3)^2}$ l\u00e0 $\\dfrac{-3 }{x-3}$ "],"explain":["<span class='basic_left'><b> Sai v\u00ec<\/b>: <br\/> Ph\u00e2n th\u1ee9c $\\dfrac{1}{100x^2-20x^3}$ c\u00f3 ngh\u0129a khi <br\/> $\\begin{aligned} & 100x^2-20x^3\\ne 0 \\\\ & \\Rightarrow 20x^2\\left( 5-x \\right)\\ne 0 \\\\ & \\Rightarrow \\left\\{ \\begin{aligned} & x^2\\ne 0 \\\\ & 5-x\\ne 0 \\\\ \\end{aligned} \\right.\\Rightarrow \\left\\{ \\begin{aligned} & x\\ne 0 \\\\ & x\\ne 5 \\\\ \\end{aligned} \\right. \\\\ \\end{aligned}$ <br\/><\/span>","<span class='basic_left'><b> \u0110\u00fang v\u00ec<\/b>: <br\/> $\\dfrac{135x-45{{x}^{2}}}{15x{{(x-3)}^{2}}}=\\dfrac{45x\\left( 3-x \\right)}{15x{{(x-3)}^{2}}}$$=\\dfrac{45x\\left( 3-x \\right)}{15x{{(3-x)}^{2}}}$$=\\dfrac{3}{3-x}=\\dfrac{-3}{x-3}$ <br\/><\/span> "]}]}],"id_ques":21},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00fang hay sai","title_trans":"","temp":"true_false","correct":[["t","t"]],"list":[{"point":5,"image":"https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai12/lv2/img\/16.jpg","col_name":["Kh\u1eb3ng \u0111\u1ecbnh","\u0110\u00fang","Sai"],"arr_ques":["Ph\u00e2n th\u1ee9c $\\dfrac{0,16x^2+0,16x}{0,4x^2-0,4x}$ c\u00f3 ngh\u0129a khi $x\\,\\ne 0;x\\ne 1$ ","K\u1ebft qu\u1ea3 r\u00fat g\u1ecdn ph\u00e2n th\u1ee9c $\\dfrac{0,16x^2+0,16x}{0,4x^2-0,4x}$ l\u00e0 $\\dfrac{0,4(x+1)}{x-1}$ "],"explain":["<span class='basic_left'><b> \u0110\u00fang v\u00ec<\/b>: <br\/> Ph\u00e2n th\u1ee9c $\\dfrac{0,16x^2+0,16x}{0,4x^2-0,4x}$ c\u00f3 ngh\u0129a khi <br\/> $\\begin{aligned} & 0,4x^2-0,4x\\ne 0 \\\\ &\\Rightarrow 0,4x\\left( x-1 \\right)\\ne 0 \\\\ & \\Rightarrow \\left\\{ \\begin{aligned} & x\\ne 0 \\\\ & x-1\\ne 0 \\\\ \\end{aligned} \\right.\\Rightarrow \\left\\{ \\begin{aligned} & x\\ne 0 \\\\ & x\\ne 1 \\\\ \\end{aligned} \\right. \\\\ \\end{aligned}$ <br\/><\/span>","<span class='basic_left'><b> \u0110\u00fang v\u00ec<\/b>: <br\/> $\\dfrac{0,16{{x}^{2}}+0,16x}{0,4{{x}^{2}}-0,4x}=\\dfrac{0,16x\\left( x+1 \\right)}{0,4x\\left( x-1 \\right)}$$=\\dfrac{0,4\\left( x+1 \\right)}{x-1}$ <br\/><\/span> "]}]}],"id_ques":22},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t cho c\u00e2u r\u00fat g\u1ecdn ph\u00e2n th\u1ee9c sau","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai12/lv2/img\/10.jpg' \/><\/center> $\\dfrac{x^3-3x^2+x-3}{2x^3+x^2+2x+1}$$=\\dfrac{(x^3-3x^2+x-3):\\square}{(2x^3+x^2+2x+1):\\square}$$=\\dfrac{x-3}{2x+1}$<br\/> Bi\u1ec3u th\u1ee9c c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng \u0111\u1ec3 \u0111\u01b0\u1ee3c ph\u00e9p r\u00fat g\u1ecdn \u0111\u00fang l\u00e0: ","select":["A. $x^2+1$ ","B. $x^2-1$ ","C. $x+1$","D. $x-1$"],"hint":" \u00d4 c\u1ea7n \u0111i\u1ec1n l\u00e0 nh\u00e2n t\u1eed chung c\u1ee7a t\u1eed th\u1ee9c v\u00e0 m\u1eabu th\u1ee9c. ","explain":"<span class='basic_left'> Ta c\u00f3: <br\/> $\\begin{align} & \\dfrac{{{x}^{3}}-3{{x}^{2}}+x-3}{2{{x}^{3}}+{{x}^{2}}+2x+1} \\\\ & =\\dfrac{{{x}^{2}}\\left( x-3 \\right)+(x-3)}{{{x}^{2}}\\left( 2x+1 \\right)+\\left( 2x+1 \\right)} \\\\ & =\\dfrac{\\left( x-3 \\right)\\left( {{x}^{2}}+1 \\right)}{\\left( 2x+1 \\right)\\left( {{x}^{2}}+1 \\right)} \\\\ & =\\dfrac{\\left( x-3 \\right)\\left( {{x}^{2}}+1 \\right):\\left( {{x}^{2}}+1 \\right)}{\\left( 2x+1 \\right)\\left( {{x}^{2}}+1 \\right):\\left( {{x}^{2}}+1 \\right)} \\\\ & =\\dfrac{x-3}{2x+1} \\\\ \\end{align}$ <br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 A. <\/span><\/span> ","column":2}]}],"id_ques":23},{"time":24,"part":[{"title":"\u0110i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng trong b\u00e0i r\u00fat g\u1ecdn ph\u00e2n th\u1ee9c sau","title_trans":"","temp":"fill_the_blank","correct":[[["5(1-x)","-5(x-1)","(5-5x)","(-5x+5)"],["5(1-x)","-5(x-1)","(5-5x)","(-5x+5)"]]],"list":[{"point":5,"width":40,"type_input":"","ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai12/lv2/img\/9.jpg' \/><\/center> $\\dfrac{15x^2-30x+15}{10y-10x^2y}$$=\\dfrac{(15x^2-30x+15):\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}}{(10y-10x^2y):\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}}$$=\\dfrac{3(1-x)}{2y(1+x)}$ ","hint":" \u00d4 c\u1ea7n \u0111i\u1ec1n l\u00e0 nh\u00e2n t\u1eed chung c\u1ee7a t\u1eed th\u1ee9c v\u00e0 m\u1eabu th\u1ee9c. ","explain":"<span class='basic_left'>Ta c\u00f3: <br\/> $\\begin{align} & \\dfrac{15{{x}^{2}}-30x+15}{10y-10{{x}^{2}}y} \\\\ & =\\dfrac{15\\left( {{x}^{2}}-2x+1 \\right)}{10y\\left( 1-{{x}^{2}} \\right)} \\\\ & =\\dfrac{15{{\\left( x-1 \\right)}^{2}}}{10y\\left( 1+x \\right)\\left( 1-x \\right)} \\\\ & =\\dfrac{15{{\\left( 1-x \\right)}^{2}}:[5\\left( 1-x \\right)]}{10y\\left( 1+x \\right)\\left( 1-x \\right):[5\\left( 1-x \\right)]} \\\\ & =\\dfrac{3\\left( 1-x \\right)}{2y\\left( 1+x \\right)} \\\\ \\end{align}$ <br\/> <span class='basic_pink'> Do \u0111\u00f3 ph\u1ea3i \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $5(1-x)$. <\/span><\/span> "}]}],"id_ques":24},{"time":24,"part":[{"title":"\u0110i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng trong b\u00e0i r\u00fat g\u1ecdn ph\u00e2n th\u1ee9c sau","title_trans":"","temp":"fill_the_blank","correct":[[["3a-4","-4+3a"],["3a-4","-4+3a"]]],"list":[{"point":5,"width":40,"type_input":"","ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai12/lv2/img\/8.jpg' \/><\/center> $\\dfrac{9a^2-16}{16-24a+9a^2}$$=\\dfrac{(9a^2-16):(\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{})}{(16-24a+9a^2):(\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{})}$$=\\dfrac{3a+4}{3a-4}$ ","explain":"<span class='basic_left'> Ta c\u00f3: <br\/> $\\begin{align} & \\dfrac{9{{a}^{2}}-16}{16-24a+9{{a}^{2}}} \\\\ & =\\dfrac{\\left( 3a+4 \\right)\\left( 3a-4 \\right)}{{{\\left( 4-3a \\right)}^{2}}} \\\\ & =\\dfrac{\\left( 3a+4 \\right)\\left( 3a-4 \\right)}{{{\\left( 3a-4 \\right)}^{2}}} \\\\ & =\\dfrac{\\left( 3a+4 \\right)\\left( 3a-4 \\right):\\left( 3a-4 \\right)}{{{\\left( 3a-4 \\right)}^{2}}:\\left( 3a-4 \\right)} \\\\ & =\\dfrac{3a+4}{3a-4} \\\\ \\end{align}$ <br\/> <span class='basic_pink'> Do \u0111\u00f3 ph\u1ea3i \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $3a-4$. <\/span><\/span> "}]}],"id_ques":25},{"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/bai12/lv2/img\/5.jpg' \/><\/center> R\u00fat g\u1ecdn ph\u00e2n th\u1ee9c $\\dfrac{4x^2-4xy+y^2}{y^2-4x^2}$ \u0111\u01b0\u1ee3c k\u1ebft qu\u1ea3 l\u00e0:","select":["A. $\\dfrac{x-y}{x-2y}$ ","B. $\\dfrac{y-2x}{2x-y}$ ","C. $\\dfrac{2x-y}{2x+y}$","D. $\\dfrac{y-2x}{2x+y}$"],"explain":"<span class='basic_left'> Ta c\u00f3: <br\/> $\\begin{align} & \\dfrac{4{{x}^{2}}-4xy+{{y}^{2}}}{{{y}^{2}}-4{{x}^{2}}} \\\\ & =\\dfrac{{{\\left( 2x-y \\right)}^{2}}}{\\left( y+2x \\right)\\left( y-2x \\right)} \\\\ & =\\dfrac{{{\\left( y-2x \\right)}^{2}}}{\\left( 2x+y \\right)\\left( y-2x \\right)} \\\\ & =\\dfrac{y-2x}{2x+y} \\\\ \\end{align}$ <span><br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 D.<\/span>","column":2}]}],"id_ques":26},{"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/bai12/lv2/img\/4.jpg' \/><\/center> R\u00fat g\u1ecdn ph\u00e2n th\u1ee9c $\\dfrac{36x-x^3}{x^3+12x^2+36x}$ \u0111\u01b0\u1ee3c k\u1ebft qu\u1ea3 l\u00e0:","select":["A. $\\dfrac{x+6}{6-x}$ ","B. $\\dfrac{6-x}{x+6}$ ","C. $\\dfrac{x+6}{x+2}$","D. $\\dfrac{6-x}{x+2}$"],"explain":"<span class='basic_left'> Ta c\u00f3: <br\/> $\\begin{align} & \\dfrac{36x-{{x}^{3}}}{{{x}^{3}}+12{{x}^{2}}+36x} \\\\ & =\\dfrac{x\\left( 36-{{x}^{2}} \\right)}{x\\left( {{x}^{2}}+12x+36 \\right)} \\\\ & =\\dfrac{x\\left( 6+x \\right)\\left( 6-x \\right)}{x{{\\left( x+6 \\right)}^{2}}} \\\\ & =\\dfrac{6-x}{x+6} \\\\ \\end{align}$ <span><br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 B.<\/span>","column":2}]}],"id_ques":27},{"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/bai12/lv2/img\/3.jpg' \/><\/center> R\u00fat g\u1ecdn ph\u00e2n th\u1ee9c $\\dfrac{2a^2-2ab}{ac+ad-bc-bd}$ \u0111\u01b0\u1ee3c k\u1ebft qu\u1ea3 l\u00e0","select":["A. $\\dfrac{2a}{c+d}$ ","B. $\\dfrac{2a}{a+b}$ ","C. $\\dfrac{-2a}{a-b}$","D. $\\dfrac{2a}{c-d}$"],"explain":"<span class='basic_left'> Ta c\u00f3: <br\/> $\\begin{align} & \\dfrac{2{{a}^{2}}-2ab}{ac+ad-bc-bd} \\\\ & =\\dfrac{2a\\left( a-b \\right)}{a\\left( c+d \\right)-b\\left( c+d \\right)} \\\\ & =\\dfrac{2a\\left( a-b \\right)}{\\left( c+d \\right)\\left( a-b \\right)} \\\\ & =\\dfrac{2a}{c+d} \\\\ \\end{align}$ <span><br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 A.<\/span>","column":2}]}],"id_ques":28},{"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/bai12/lv2/img\/2.jpg' \/><\/center> Gi\u00e1 tr\u1ecb c\u1ee7a ph\u00e2n th\u1ee9c $\\dfrac{x+1}{x^3-2x^2+x}$ t\u1ea1i $x = -1$ l\u00e0 _input_ ","hint":"R\u00fat g\u1ecdn ph\u00e2n th\u1ee9c sau \u0111\u00f3 thay $x = -1$ v\u00e0o ph\u00e2n th\u1ee9c \u0111\u1ec3 t\u00ednh. ","explain":"<span class='basic_left'> Ta c\u00f3: <br\/> $\\begin{align} & \\dfrac{x+1}{x^3-2x^2+x} \\\\ & =\\dfrac{x+1}{x(x^2-2x+1)} \\\\ & =\\dfrac{x+1}{x(x-1)^2} \\\\ \\end{align}$ <br\/> Thay $x = -1$ v\u00e0o ph\u00e2n th\u1ee9c r\u00fat g\u1ecdn, ta \u0111\u01b0\u1ee3c:<br\/> $\\dfrac{x+1}{x(x-1)^2}=\\dfrac{-1+1}{-1.(-1-1)^2}=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":29},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["2011"]]],"list":[{"point":5,"width":40,"type_input":"","ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai12/lv2/img\/16.jpg' \/><\/center> Gi\u00e1 tr\u1ecb c\u1ee7a ph\u00e2n th\u1ee9c $\\dfrac{x^2-4x-5}{x+1}$ t\u1ea1i $x = 2016$ l\u00e0 _input_ ","hint":"R\u00fat g\u1ecdn ph\u00e2n th\u1ee9c sau \u0111\u00f3 thay $x = 2016$ v\u00e0o ph\u00e2n th\u1ee9c \u0111\u1ec3 t\u00ednh. ","explain":"<span class='basic_left'> Ta c\u00f3: <br\/> $\\begin{align} & \\dfrac{x^2-4x-5}{x+1} \\\\ & =\\dfrac{x^2-5x+x-5}{x+1} \\\\ & =\\dfrac{x(x-5)+(x-5)}{x+1} \\\\ & =\\dfrac{(x+1)(x-5)}{x+1} \\\\ & =x-5 \\\\ \\end{align}$ <br\/> Thay $x =2016$ v\u00e0o ph\u00e2n th\u1ee9c r\u00fat g\u1ecdn, ta \u0111\u01b0\u1ee3c:<br\/> $x-5 = 2016 - 5 = 2011$ <br\/> <span class='basic_pink'> Do \u0111\u00f3 ph\u1ea3i \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $2011$. <\/span><\/span> "}]}],"id_ques":30},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["27"]]],"list":[{"point":5,"width":40,"type_input":"","ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai12/lv2/img\/13.jpg' \/><\/center> Gi\u00e1 tr\u1ecb c\u1ee7a ph\u00e2n th\u1ee9c $\\dfrac{3x^2(x+1)}{x+1}$ t\u1ea1i $x = -3$ l\u00e0 _input_ ","explain":"<span class='basic_left'> Ta c\u00f3: <br\/> $\\begin{align} & \\dfrac{3x^2(x+1)}{x+1} \\\\ & =\\dfrac{3x^2(x+1):(x+1)}{(x+1):(x+1)} \\\\ & =3x^2 \\\\ \\end{align}$ <br\/> Thay $x = -3$ v\u00e0o ph\u00e2n th\u1ee9c r\u00fat g\u1ecdn, ta \u0111\u01b0\u1ee3c:<br\/> $3x^2=3.(-3)^2=27$ <br\/> <span class='basic_pink'> Do \u0111\u00f3 ph\u1ea3i \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $27$. <\/span><\/span> "}]}],"id_ques":31},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank_random","correct":[[["1"],["-6"]]],"list":[{"point":5,"width":40,"type_input":"","ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai12/lv2/img\/12.jpg' \/><\/center> Ph\u00e2n th\u1ee9c $\\dfrac{xy}{x^2+5x-6}$ c\u00f3 ngh\u0129a khi $\\left\\{ \\begin{align} & x\\ne \\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{} \\\\ & x\\ne \\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{} \\\\ \\end{align} \\right.$ ","explain":"<span class='basic_left'> Ph\u00e2n th\u1ee9c $\\dfrac{xy}{x^2+5x-6}$ c\u00f3 ngh\u0129a khi <br\/> $\\begin{aligned} & {{x}^{2}}+5x-6\\,\\,\\ne 0 \\\\ & \\Rightarrow{{x}^{2}}-x+6x-6\\,\\,\\ne 0 \\\\ &\\Rightarrow x(x-1)+6(x-1)\\,\\,\\ne 0 \\\\ &\\Rightarrow \\left( x-1 \\right)\\left( x+6 \\right)\\,\\,\\ne 0 \\\\ & \\Rightarrow \\left\\{ \\begin{aligned} & x-1\\ne 0 \\\\ & x+6\\ne 0 \\\\ \\end{aligned} \\right.\\Rightarrow \\left\\{ \\begin{aligned} & x\\ne 1 \\\\ & x\\ne -6 \\\\ \\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 $-6$. <\/span><\/span> "}]}],"id_ques":32},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank_random","correct":[[["2"],["-3"]]],"list":[{"point":5,"width":40,"type_input":"","ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai12/lv2/img\/11.jpg' \/><\/center> Ph\u00e2n th\u1ee9c $\\dfrac{1}{(x-2)(x+3)}$ c\u00f3 ngh\u0129a khi $\\left\\{ \\begin{align} & x\\ne \\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{} \\\\ & x\\ne \\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{} \\\\ \\end{align} \\right.$ ","explain":"<span class='basic_left'> Ph\u00e2n th\u1ee9c $\\dfrac{1}{(x-2)(x+3)}$ c\u00f3 ngh\u0129a khi <br\/> $ (x-2)(x+3)\\,\\,\\ne 0 \\Rightarrow \\left\\{ \\begin{aligned} & x-2\\ne 0 \\\\ & x+3\\ne 0 \\\\ \\end{aligned} \\right.$$\\Rightarrow \\left\\{ \\begin{aligned} & x\\ne 2 \\\\ & x\\ne -3 \\\\ \\end{aligned} \\right. $ <br\/> <span class='basic_pink'> Do \u0111\u00f3 ph\u1ea3i \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $2$ v\u00e0 $-3$. <\/span><\/span> "}]}],"id_ques":33},{"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/bai12/lv2/img\/10.jpg' \/><\/center> Ph\u00e2n th\u1ee9c $\\dfrac{(9-x)^2}{x-2}$ c\u00f3 ngh\u0129a khi $x\\,\\ne \\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}$ ","explain":"<span class='basic_left'> Ph\u00e2n th\u1ee9c $\\dfrac{(9-x)^2}{x-2}$ c\u00f3 ngh\u0129a khi $x-2\\,\\ne 0 \\Rightarrow x\\,\\ne 2$ <br\/> <span class='basic_pink'> Do \u0111\u00f3 ph\u1ea3i \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $2$. <\/span><\/span> "}]}],"id_ques":34},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t.<br\/> Kh\u1eb3ng \u0111\u1ecbnh d\u01b0\u1edbi \u0111\u00e2y \u0111\u00fang hay sai","title_trans":"","temp":"multiple_choice","correct":[[2]],"list":[{"point":5,"ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai12/lv2/img\/9.jpg' \/><\/center> $\\dfrac{1}{x+1}$ v\u00e0 $\\dfrac{x(x^2-1)}{x^2-x}$ l\u00e0 hai ph\u00e2n th\u1ee9c b\u1eb1ng nhau. ","select":["\u0110\u00fang","Sai"],"explain":"<span class='basic_left'> R\u00fat g\u1ecdn ph\u00e2n th\u1ee9c: <br\/> $\\dfrac{x(x^2-1)}{x^2-x}=\\dfrac{x(x+1)(x-1)}{x(x-1)}$$=x+1\\ne \\dfrac{1}{x+1}$ <span><br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 Sai.<\/span>","column":2}]}],"id_ques":35},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t.<br\/> Kh\u1eb3ng \u0111\u1ecbnh d\u01b0\u1edbi \u0111\u00e2y \u0111\u00fang hay sai","title_trans":"","temp":"multiple_choice","correct":[[2]],"list":[{"point":5,"ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai12/lv2/img\/8.jpg' \/><\/center> $\\dfrac{x^2}{x+2}$ v\u00e0 $\\dfrac{x^2(x-2)^2}{x^2-4}$ l\u00e0 hai ph\u00e2n th\u1ee9c b\u1eb1ng nhau ","select":["\u0110\u00fang","Sai"],"explain":"<span class='basic_left'> R\u00fat g\u1ecdn ph\u00e2n th\u1ee9c: <br\/> $\\dfrac{x^2(x-2)^2}{x^2-4}=\\dfrac{x^2(x-2)^2}{(x+2)(x-2)}$$=\\dfrac{x^2(x-2)}{x+2}\\ne \\dfrac{x^2}{x+2}$ <span><br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 Sai. <\/span>","column":2}]}],"id_ques":36},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t.<br\/> Kh\u1eb3ng \u0111\u1ecbnh d\u01b0\u1edbi \u0111\u00e2y \u0111\u00fang hay sai","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai12/lv2/img\/5.jpg' \/><\/center> $\\dfrac{x+4}{y}$ v\u00e0 $\\dfrac{(x+4)^2}{y(x+4)}$ l\u00e0 hai ph\u00e2n th\u1ee9c b\u1eb1ng nhau ","select":["\u0110\u00fang","Sai"],"explain":" R\u00fat g\u1ecdn ph\u00e2n th\u1ee9c: <br\/> $\\dfrac{(x+4)^2}{y(x+4)}=\\dfrac{x+4}{y}$ <span><br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 \u0110\u00fang.<\/span>","column":2}]}],"id_ques":37},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 v\u00e0o \u00f4 tr\u1ed1ng trong c\u00e2u r\u00fat g\u1ecdn ph\u00e2n th\u1ee9c sau","title_trans":"","temp":"fill_the_blank","correct":[[["7y"]]],"list":[{"point":5,"width":40,"type_input":"","ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai12/lv2/img\/4.jpg' \/><\/center> $\\dfrac{7x^2y^3}{49x^2y^4}=\\dfrac{1}{\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}}$ ","explain":"<span class='basic_left'> Ta c\u00f3:<br\/> $\\dfrac{7x^2y^3}{49x^2y^4}=\\dfrac{7x^2y^3:7x^2y^3}{49x^2y^4:7x^2y^3}=\\dfrac{1}{7y}$ <br\/> <span class='basic_pink'> Do \u0111\u00f3 ph\u1ea3i \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $7y$. <\/span><\/span> "}]}],"id_ques":38},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 v\u00e0o \u00f4 tr\u1ed1ng trong c\u00e2u r\u00fat g\u1ecdn ph\u00e2n th\u1ee9c sau","title_trans":"","temp":"fill_the_blank","correct":[[["4-y","-y+4"]]],"list":[{"point":5,"width":40,"type_input":"","ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai12/lv2/img\/3.jpg' \/><\/center> $\\dfrac{16-y^2}{y(4+y)}=\\dfrac{\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}}{y}$ ","explain":"<span class='basic_left'> Ta c\u00f3:<br\/> $\\dfrac{16-y^2}{y(4+y)}=\\dfrac{(4+y)(4-y)}{y(4+y)}=\\dfrac{4-y}{y}$ <br\/> <span class='basic_pink'> Do \u0111\u00f3 ph\u1ea3i \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $4-y$. <\/span><\/span> "}]}],"id_ques":39},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 v\u00e0o \u00f4 tr\u1ed1ng trong c\u00e2u r\u00fat g\u1ecdn ph\u00e2n th\u1ee9c sau","title_trans":"","temp":"fill_the_blank","correct":[[["x+1","1+x"]]],"list":[{"point":5,"width":40,"type_input":"","ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai12/lv2/img\/2.jpg' \/><\/center> $\\dfrac{x^2-x+1}{x^3+1}=\\dfrac{1}{\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}}$ ","explain":"<span class='basic_left'> Ta c\u00f3:<br\/> $\\dfrac{x^2-x+1}{x^3+1}=\\dfrac{x^2-x+1}{(x+1)(x^2-x+1)}$$=\\dfrac{1}{x+1}$ <br\/> <span class='basic_pink'> Do \u0111\u00f3 ph\u1ea3i \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $x+1$. <\/span><\/span> "}]}],"id_ques":40}],"lesson":{"save":0,"level":2}}