{"segment":[{"time":24,"part":[{"title":"\u0110i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["y-1","-1+y"],["y-1","-1+y"]]],"list":[{"point":5,"width":40,"type_input":"","ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai12/lv1/img\/10.jpg' \/><\/center> $\\dfrac{1}{y}=\\dfrac{1\\times (\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{})}{y\\times (\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{})}=\\dfrac{y-1}{y^2-y}$ ","hint":" \u00c1p d\u1ee5ng theo t\u00ednh ch\u1ea5t ph\u00e2n th\u1ee9c: $\\dfrac{A}{B}=\\dfrac{A.M}{B.M}\\,\\,\\left( M\\ne 0 \\right)$ ","explain":"<span class='basic_left'> Theo t\u00ednh ch\u1ea5t c\u1ee7a ph\u00e2n th\u1ee9c, ta c\u00f3: <br\/> $\\dfrac{1}{y}=\\dfrac{1.\\left( y-1 \\right)}{y.\\left( y-1 \\right)}=\\dfrac{y-1}{{{y}^{2}}-y}$ v\u1edbi $y\\ne 1$ <br\/> <span class='basic_pink'> Do \u0111\u00f3 ph\u1ea3i \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $y-1$. <\/span><\/span> "}]}],"id_ques":1},{"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":[[["2-3x","-3x+2"],["2-3x","-3x+2"]]],"list":[{"point":5,"width":40,"type_input":"","ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai12/lv1/img\/9.jpg' \/><\/center> $\\dfrac{4-9x^2}{4-6x}=\\dfrac{(4-9x^2):(\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{})}{(4-6x):(\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{})}$$=\\dfrac{2+3x}{2}$ ","hint":" \u00d4 c\u1ea7n \u0111i\u1ec1n l\u00e0 nh\u00e2n t\u1eed chung c\u1ee7a t\u1eed th\u1ee9c v\u00e0 m\u1eabu th\u1ee9c. ","explain":"<span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> <b> Mu\u1ed1n r\u00fat g\u1ecdn ph\u00e2n th\u1ee9c:<\/b> <br\/> + Ph\u00e2n t\u00edch c\u1ea3 t\u1eed v\u00e0 m\u1eabu th\u00e0nh nh\u00e2n t\u1eed (n\u1ebfu c\u1ea7n) \u0111\u1ec3 t\u00ecm nh\u00e2n t\u1eed chung.<br\/> + Chia c\u1ea3 t\u1eed v\u00e0 m\u1eabu cho nh\u00e2n t\u1eed chung. <br\/> Do \u0111\u00f3 \u00f4 c\u1ea7n \u0111i\u1ec1n l\u00e0 nh\u00e2n t\u1eed chung c\u1ee7a t\u1eed th\u1ee9c v\u00e0 m\u1eabu th\u1ee9c.<br\/><span class='basic_green'>Gi\u1ea3i<\/span><br\/><span class='basic_left'>R\u00fat g\u1ecdn ph\u00e2n th\u1ee9c:<br\/> $\\dfrac{4-9{{x}^{2}}}{4-6x}\\\\ =\\dfrac{\\left( 2+3x \\right)\\left( 2-3x \\right)}{2\\left( 2-3x \\right)}$ <br\/> $=\\dfrac{\\left( 2+3x \\right)\\left( 2-3x \\right):(2-3x)}{2\\left( 2-3x \\right):\\left( 2-3x \\right)}$ <br\/> $=\\dfrac{2+3x}{2}$ <br\/> <span class='basic_pink'> Do \u0111\u00f3 ph\u1ea3i \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $2-3x$. <\/span><\/span> "}]}],"id_ques":2},{"time":24,"part":[{"title":"\u0110i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng trong b\u00e0i r\u00fat g\u1ecdn ph\u00e2n th\u1ee9c sau","title_trans":"","temp":"fill_the_blank","correct":[[["2xy"],["2xy"]]],"list":[{"point":5,"width":40,"type_input":"","ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai12/lv1/img\/8.jpg' \/><\/center> $\\dfrac{2x{{y}^{2}}}{6xy}=\\dfrac{2x{{y}^{2}}:\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}}{6xy:\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}}$$=\\dfrac{y}{3}$ ","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\/> $\\dfrac{2x{{y}^{2}}}{6xy} =\\dfrac{2x{{y}^{2}}:2xy}{6xy:2xy}$ $=\\dfrac{y}{3}$ <br\/> <span class='basic_pink'> Do \u0111\u00f3 ph\u1ea3i \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $2xy$. <\/span><\/span> "}]}],"id_ques":3},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00fang hay sai","title_trans":"","temp":"true_false","correct":[["t","f"]],"list":[{"point":5,"col_name":["Kh\u1eb3ng \u0111\u1ecbnh","\u0110\u00fang","Sai"],"arr_ques":["Ph\u00e2n th\u1ee9c $\\dfrac{12}{x^2-1}$ c\u00f3 ngh\u0129a khi $x\\,\\ne \\pm 1$ "," K\u1ebft qu\u1ea3 r\u00fat g\u1ecdn ph\u00e2n th\u1ee9c $\\dfrac{x-1}{(x+1)(x-1)}$ l\u00e0 $-\\dfrac{1}{x+1}$ "],"explain":["<span class='basic_left'><b> \u0110\u00fang v\u00ec<\/b>: Ph\u00e2n th\u1ee9c $\\dfrac{12}{x^2-1}$ c\u00f3 ngh\u0129a khi $x^2-1\\,\\ne 0 \\Rightarrow x\\ne \\pm 1$ <br\/><\/span>","<span class='basic_left'><b> Sai v\u00ec:<\/b> $\\dfrac{x-1}{(x+1)(x-1)}=\\dfrac{1}{x+1}$ <br\/><\/span> "]}]}],"id_ques":4},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00fang hay sai","title_trans":"","temp":"true_false","correct":[["t","t"]],"list":[{"point":5,"col_name":["Kh\u1eb3ng \u0111\u1ecbnh","\u0110\u00fang","Sai"],"arr_ques":["V\u1edbi $x=-0,4$ th\u00ec gi\u00e1 tr\u1ecb ph\u00e2n th\u1ee9c $\\dfrac{1,4}{1-x}$ l\u00e0 $1$ ","V\u1edbi $x=-5$ th\u00ec gi\u00e1 tr\u1ecb ph\u00e2n th\u1ee9c $\\dfrac{6}{x-1}$ l\u00e0 $-1$ "],"explain":["<span class='basic_left'><b> \u0110\u00fang v\u00ec<\/b>: Thay $x=-0,4$ v\u00e0o ph\u00e2n th\u1ee9c, ta \u0111\u01b0\u1ee3c $\\dfrac{1,4}{1-x}= \\dfrac{1,4}{1+0,4}=1$ <br\/><\/span>","<span class='basic_left'><b> \u0110\u00fang v\u00ec:<\/b> Thay $x=-5$ v\u00e0o ph\u00e2n th\u1ee9c, ta \u0111\u01b0\u1ee3c $\\dfrac{6}{x-1}= \\dfrac{6}{-5-1}=-1$ <br\/><\/span> "]}]}],"id_ques":5},{"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/lv1/img\/5.jpg' \/><\/center> R\u00fat g\u1ecdn ph\u00e2n th\u1ee9c $\\dfrac{a^3-27}{2a-6}$ \u0111\u01b0\u1ee3c k\u1ebft qu\u1ea3 l\u00e0:","select":["A. $\\dfrac{a^2+a+3}{2}$ ","B. $\\dfrac{a^2+3a+9}{2(a+1)}$ ","C. $\\dfrac{a-3}{2}$","D. $\\dfrac{a^2+3a+9}{2}$"],"explain":"<span class='basic_left'>Ta c\u00f3: <br\/> $\\dfrac{{{a}^{3}}-27}{2a-6}\\\\ =\\dfrac{\\left( a-3 \\right)\\left( {{a}^{2}}+3a+9 \\right)}{2\\left( a-3 \\right)}$ <br\/> $=\\dfrac{\\left( a-3 \\right)\\left( {{a}^{2}}+3a+9 \\right):\\left( a-3 \\right)}{2\\left( a-3 \\right):\\left( a-3 \\right)}$ <br\/> $=\\dfrac{{{a}^{2}}+3a+9}{2}$ <span><br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 D.<\/span>","column":2}]}],"id_ques":6},{"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/lv1/img\/4.jpg' \/><\/center> R\u00fat g\u1ecdn ph\u00e2n th\u1ee9c $\\dfrac{2y-2x}{x^2-2xy+y^2}$ \u0111\u01b0\u1ee3c k\u1ebft qu\u1ea3 l\u00e0:","select":["A. $\\dfrac{-2}{x+y}$ ","B. $\\dfrac{2}{y-x}$ ","C. $\\dfrac{2(x-y)}{x+y}$","D. $\\dfrac{2}{x-y}$"],"explain":"<span class='basic_left'> Ta c\u00f3: <br\/> $\\dfrac{2y-2x}{{{x}^{2}}-2xy+{{y}^{2}}} \\\\ =\\dfrac{2\\left( y-x \\right)}{{{\\left( x-y \\right)}^{2}}}\\\\ =\\dfrac{2\\left( y-x \\right)}{{{\\left( y-x \\right)}^{2}}}$ <br\/> $=\\dfrac{2\\left( y-x \\right):\\left( y-x \\right)}{{{\\left( y-x \\right)}^{2}}:\\left( y-x \\right)}$ <br\/> $=\\dfrac{2}{y-x}$<br\/><span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 B.<\/span><br\/><span class='basic_green'>Ghi nh\u1edb: $(a-b)^2=(b-a)^2$<\/span> <span>","column":2}]}],"id_ques":7},{"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/bai12/lv1/img\/3.jpg' \/><\/center> R\u00fat g\u1ecdn ph\u00e2n th\u1ee9c $\\dfrac{2-2a}{a^3-1}$ \u0111\u01b0\u1ee3c k\u1ebft qu\u1ea3 l\u00e0:","select":["A. $\\dfrac{1}{a-1}$ ","B. $\\dfrac{2}{a+1}$ ","C. $\\dfrac{-2}{a^2+a+1}$","D. $\\dfrac{2}{a^2+a+1}$"],"explain":"<span class='basic_left'>Ta c\u00f3: <br\/> $\\dfrac{2-2a}{{{a}^{3}}-1}\\\\ =\\dfrac{2\\left( 1-a \\right)}{\\left( a-1 \\right)\\left( {{a}^{2}}+a+1 \\right)}$ <br\/> $=\\dfrac{-2\\left( a-1 \\right):\\left( a-1 \\right)}{\\left( a-1 \\right)\\left( {{a}^{2}}+a+1 \\right):\\left( a-1 \\right)}$ <br\/> $=\\dfrac{-2}{{{a}^{2}}+a+1}$ <span><br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 C.<\/span>","column":2}]}],"id_ques":8},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["21"]]],"list":[{"point":5,"width":40,"type_input":"","ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai12/lv1/img\/2.jpg' \/><\/center> Gi\u00e1 tr\u1ecb c\u1ee7a ph\u00e2n th\u1ee9c $\\dfrac{x^3+1}{x+1}$ t\u1ea1i $x = 5$ l\u00e0 _input_ ","hint":" R\u00fat g\u1ecdn ph\u00e2n th\u1ee9c r\u1ed3i thay $x = 5$ v\u00e0o ph\u00e2n th\u1ee9c \u0111\u1ec3 t\u00ednh. ","explain":"<span class='basic_left'>Ta c\u00f3: <br\/> $\\begin{align} & \\dfrac{{{x}^{3}}+1}{x+1} \\\\ & =\\dfrac{\\left( x+1 \\right)\\left( {{x}^{2}}-x+1 \\right)}{x+1} \\\\ & =\\dfrac{\\left( x+1 \\right)\\left( {{x}^{2}}-x+1 \\right):\\left( x+1 \\right)}{\\left( x+1 \\right):\\left( x+1 \\right)} \\\\ & ={{x}^{2}}-x+1 \\\\ \\end{align}$ <br\/> Thay $x = 5$ v\u00e0o ph\u00e2n th\u1ee9c r\u00fat g\u1ecdn, ta \u0111\u01b0\u1ee3c:<br\/> $x^2-x+1=5^2-5+1=21$ <br\/> <span class='basic_pink'> Do \u0111\u00f3 ph\u1ea3i \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 21. <\/span><\/span> "}]}],"id_ques":9},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["-9"],["4"]]],"list":[{"point":5,"width":50,"type_input":"","input_hint":["frac"],"ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai12/lv1/img\/16.jpg' \/><\/center> Gi\u00e1 tr\u1ecb c\u1ee7a ph\u00e2n th\u1ee9c $\\dfrac{2xy}{1-xy}$ t\u1ea1i $x = y =3$ l\u00e0: <div class=\"frac123\"><div class=\"ts\">_input_<\/div><div class=\"ms\">_input_<\/div><\/div>","explain":"<span class='basic_left'> Thay $x = y=3$ v\u00e0o ph\u00e2n th\u1ee9c, ta \u0111\u01b0\u1ee3c:<br\/> $\\dfrac{2xy}{1-xy}=\\dfrac{2.3.3}{1-3.3}=\\dfrac{18}{-8}=\\dfrac{-9}{4}$<\/span>"}]}],"id_ques":10},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 v\u00e0o \u00f4 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/bai12/lv1/img\/13.jpg' \/><\/center> Gi\u00e1 tr\u1ecb c\u1ee7a ph\u00e2n th\u1ee9c $\\dfrac{1}{x+y}$ t\u1ea1i $x = 3; y = -2$ l\u00e0 _input_ ","explain":"<span class='basic_left'> Thay $x = 3; y = -2$ v\u00e0o ph\u00e2n th\u1ee9c, ta \u0111\u01b0\u1ee3c:<br\/> $\\dfrac{1}{x+y}=\\dfrac{1}{3-2}=1$ <br\/> <span class='basic_pink'> Do \u0111\u00f3 ph\u1ea3i \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $1$. <\/span><\/span> "}]}],"id_ques":11},{"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/bai12/lv1/img\/12.jpg' \/><\/center> Ph\u00e2n th\u1ee9c $\\dfrac{x^2-1}{x^3-4x}$ c\u00f3 ngh\u0129a khi $\\left\\{ \\begin{align} & x\\ne \\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{} \\\\ & x\\ne \\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{} \\\\ & x\\ne \\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{} \\end{align} \\right.$ ","hint":" Ph\u00e2n th\u1ee9c c\u00f3 ngh\u0129a khi m\u1eabu c\u1ee7a ph\u00e2n th\u1ee9c kh\u00e1c $0$. ","explain":"<span class='basic_left'> Ph\u00e2n th\u1ee9c $\\dfrac{x^2-1}{x^3-4x}$ c\u00f3 ngh\u0129a khi <br\/> $\\begin{aligned} & x^3-4x\\,\\,\\ne 0 \\\\ & \\Rightarrow x(x+2)(x-2)\\,\\,\\ne 0 \\\\ & \\Rightarrow \\left\\{ \\begin{aligned} & x\\ne 0 \\\\ & x+2\\ne 0 \\\\ & x-2\\ne 0 \\\\ \\end{aligned} \\right.\\Rightarrow \\left\\{ \\begin{aligned} & x\\ne 0 \\\\ & x\\ne -2 \\\\ & x\\ne 2 \\\\ \\end{aligned} \\right. \\\\ \\end{aligned}$ <br\/> <span class='basic_pink'> Do \u0111\u00f3 ph\u1ea3i \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $0; -2$ v\u00e0 $2$. <\/span><\/span> "}]}],"id_ques":12},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank_random","correct":[[["0"],["-3"]]],"list":[{"point":5,"width":40,"type_input":"","ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai12/lv1/img\/11.jpg' \/><\/center> Ph\u00e2n th\u1ee9c $\\dfrac{3(x+1)}{x(x+3)}$ 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 $\\dfrac{3(x+1)}{x(x+3)}$ c\u00f3 ngh\u0129a khi <br\/> $\\begin{aligned} & x(x+3)\\,\\,\\ne 0 \\\\ & \\Rightarrow \\left\\{ \\begin{aligned} & x\\ne 0 \\\\ & x+3\\ne 0 \\\\ \\end{aligned} \\right.\\Rightarrow \\left\\{ \\begin{aligned} & x\\ne 0 \\\\ & x\\ne -3 \\\\ \\end{aligned} \\right. \\\\ \\end{aligned}$ <br\/> <span class='basic_pink'> Do \u0111\u00f3 ph\u1ea3i \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $0$ v\u00e0 $-3$. <\/span><\/span> "}]}],"id_ques":13},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["y"]]],"list":[{"point":5,"width":40,"type_input":"","ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai12/lv1/img\/10.jpg' \/><\/center> Ph\u00e2n th\u1ee9c $\\dfrac{1}{x-y}$ 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 $\\dfrac{1}{x-y}$ c\u00f3 ngh\u0129a khi $x-y\\,\\ne 0 \\Rightarrow x\\,\\ne y$ <br\/> <span class='basic_pink'> Do \u0111\u00f3 ph\u1ea3i \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $y$. <\/span><\/span> "}]}],"id_ques":14},{"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/lv1/img\/9.jpg' \/><\/center> Ph\u00e2n th\u1ee9c n\u00e0o sau \u0111\u00e2y b\u1eb1ng v\u1edbi ph\u00e2n th\u1ee9c $\\dfrac{-x+y}{-x-y}$","select":["A. $\\dfrac{x-y}{x+y}$ ","B. $\\dfrac{x+y}{x-y}$ ","C. $\\dfrac{y-x}{x+y}$","D. $\\dfrac{-x-y}{x-y}$"],"hint":" R\u00fat g\u1ecdn ph\u00e2n th\u1ee9c (n\u1ebfu c\u00f3 th\u1ec3) \u0111\u1ec3 t\u00ecm ph\u00e2n th\u1ee9c b\u1eb1ng v\u1edbi ph\u00e2n th\u1ee9c \u0111\u00e3 cho.","explain":"><span class='basic_left'> Ta c\u00f3:<br\/> $\\dfrac{-x+y}{-x-y} =\\dfrac{-\\left( x-y \\right)}{-\\left( x+y \\right)} $ $=\\dfrac{x-y}{x+y}$ <span><br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 A.<\/span>","column":2}]}],"id_ques":15},{"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/lv1/img\/8.jpg' \/><\/center> Ph\u00e2n th\u1ee9c n\u00e0o sau \u0111\u00e2y b\u1eb1ng v\u1edbi $xy$","select":["A. $\\dfrac{2x^2y^2}{2xy}$ ","B. $\\dfrac{xy}{x^2y^2}$ ","C. $\\dfrac{x^2}{y^2}$","D. $\\dfrac{x^2y^2}{y^2}$"],"explain":"<span class='basic_left'> Ta \u0111i r\u00fat g\u1ecdn t\u1eebng ph\u00e2n th\u1ee9c \u1edf c\u00e1c \u0111\u00e1p \u00e1n:<br\/> $\\begin{align} & \\circ \\,\\,\\,\\dfrac{2{{x}^{2}}{{y}^{2}}}{2xy}=\\dfrac{2{{x}^{2}}{{y}^{2}}:2xy}{2xy:2xy}=\\dfrac{xy}{1}=xy \\\\ & \\circ \\,\\,\\,\\dfrac{xy}{{{x}^{2}}{{y}^{2}}}=\\dfrac{xy:xy}{{{x}^{2}}{{y}^{2}}:xy}=\\dfrac{1}{xy} \\\\ & \\circ \\,\\,\\,\\dfrac{{{x}^{2}}}{{{y}^{2}}} \\\\ & \\circ \\,\\,\\dfrac{{{x}^{2}}{{y}^{2}}}{{{y}^{2}}}=\\dfrac{{{x}^{2}}{{y}^{2}}:{{y}^{2}}}{{{y}^{2}}:{{y}^{2}}}=\\dfrac{{{x}^{2}}}{1}={{x}^{2}} \\\\ \\end{align}$ <span><br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 A.<\/span>","column":2}]}],"id_ques":16},{"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/bai12/lv1/img\/5.jpg' \/><\/center> Ph\u00e2n th\u1ee9c n\u00e0o sau \u0111\u00e2y b\u1eb1ng v\u1edbi ph\u00e2n th\u1ee9c $\\dfrac{x^2y}{x^2}$","select":["A. $\\dfrac{1}{y}$ ","B. $\\dfrac{x}{y}$ ","C. $y$","D. $xy$"],"hint":" R\u00fat g\u1ecdn ph\u00e2n th\u1ee9c (n\u1ebfu c\u00f3 th\u1ec3) \u0111\u1ec3 t\u00ecm ph\u00e2n th\u1ee9c b\u1eb1ng v\u1edbi ph\u00e2n th\u1ee9c \u0111\u00e3 cho.","explain":"<span class='basic_left'> Ta c\u00f3: <br\/> $\\dfrac{{{x}^{2}}y}{{{x}^{2}}}$ $=\\dfrac{{{x}^{2}}y:{{x}^{2}}}{{{x}^{2}}:{{x}^{2}}}$ $=\\dfrac{y}{1}$ $=y$ <span><br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 C.<\/span>","column":2}]}],"id_ques":17},{"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+y","y+x"]]],"list":[{"point":5,"width":40,"type_input":"","ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai12/lv1/img\/4.jpg' \/><\/center> $\\dfrac{(x+y)^2}{(x+y)^3}=\\dfrac{1}{\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}}$ ","explain":"<span class='basic_left'> Ta c\u00f3:<br\/> $\\dfrac{{{\\left( x+y \\right)}^{2}}}{{{\\left( x+y \\right)}^{3}}}$ <br\/> $=\\dfrac{{{\\left( x+y \\right)}^{2}}:{{\\left( x+y \\right)}^{2}}}{{{\\left( x+y \\right)}^{3}}:{{\\left( x+y \\right)}^{2}}}$ <br\/> $=\\dfrac{1}{x+y}$ <br\/> <span class='basic_pink'> Do \u0111\u00f3 ph\u1ea3i \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $x+y$. <\/span><\/span> "}]}],"id_ques":18},{"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"]]],"list":[{"point":5,"width":40,"type_input":"","ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai12/lv1/img\/3.jpg' \/><\/center> $\\dfrac{2x+10}{x^2+5x}=\\dfrac{2}{\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}}$ ","explain":"<span class='basic_left'> Ta c\u00f3:<br\/> $\\dfrac{2x+10}{{{x}^{2}}+5x} \\\\ =\\dfrac{2\\left( x+5 \\right)}{x\\left( x+5 \\right)}$ <br\/> $=\\dfrac{2\\left( x+5 \\right):\\left( x+5 \\right)}{x\\left( x+5 \\right):\\left( x+5 \\right)}$ <br\/> $=\\dfrac{2}{x}$ <br\/> <span class='basic_pink'> Do \u0111\u00f3 ph\u1ea3i \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $x$. <\/span><\/span> "}]}],"id_ques":19},{"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":[[["y"]]],"list":[{"point":5,"width":40,"type_input":"","ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai12/lv1/img\/2.jpg' \/><\/center> $\\dfrac{{{x}^{2}}y}{{{x}^{2}}{{y}^{2}}}=\\dfrac{1}{\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}}$ ","explain":"<span class='basic_left'> Ta c\u00f3: <br\/> $\\dfrac{{{x}^{2}}y}{{{x}^{2}}{{y}^{2}}}=\\dfrac{{{x}^{2}}y:(x^2y)}{{{x}^{2}}{{y}^{2}}:(x^2y)}$ $=\\dfrac{1}{y}$ <br\/> <span class='basic_pink'> Do \u0111\u00f3 ph\u1ea3i \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $y$. <\/span><\/span> "}]}],"id_ques":20}],"lesson":{"save":0,"level":1}}