{"segment":[{"time":24,"part":[{"title":"\u0110i\u1ec1n d\u1ea5u $> ,<, =$ th\u00edch h\u1ee3p v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["<"]]],"list":[{"point":5,"width":40,"content":"","type_input":"","type_check":"","ques":"$\\sqrt{16+9}$ _input_ $\\sqrt{16}+\\sqrt{9}$","hint":"T\u00ednh t\u1eebng v\u1ebf r\u1ed3i so s\u00e1nh ","explain":"<span class='basic_left'>Ta c\u00f3: <br\/>$\\sqrt{16+9}=\\sqrt{25} =5$; <br\/>$\\sqrt{16}+\\sqrt{9}=4+3=7$<br\/>M\u00e0: $5 < 7 \\Rightarrow \\sqrt{16+9} < \\sqrt{16}+\\sqrt{9}$ <br\/><span class='basic_pink'>V\u1eady d\u1ea5u c\u1ea7n \u0111i\u1ec1n l\u00e0 d\u1ea5u $<$ <\/span><br\/><i>Nh\u1eadn x\u00e9t:<\/i><br\/>V\u1edbi $a,b \\ge 0$, ta c\u00f3 $\\sqrt{a+b} \\le \\sqrt{a}+\\sqrt{b}$<\/span>"}]}],"id_ques":511},{"time":24,"part":[{"title":"\u0110i\u1ec1n s\u1ed1 th\u00edch h\u1ee3p v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["-3"]]],"list":[{"point":5,"width":40,"content":"","type_input":"","type_check":"","ques":"V\u1edbi $x <0, y\\ne 0$. R\u00fat g\u1ecdn bi\u1ec3u th\u1ee9c sau: <br\/>$x{{y}^{4}}\\sqrt{\\dfrac{9}{{{x}^{2}}{{y}^{8}}}}=$ _input_","hint":"\u00c1p d\u1ee5ng: V\u1edbi $A$ l\u00e0 m\u1ed9t bi\u1ec3u th\u1ee9c, ta c\u00f3 $\\sqrt{A^2}=|A|=\\left\\{ \\begin{align} & A\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\text{n\u1ebfu}\\,\\,{A}\\ge {0} \\\\ & -A\\,\\,\\,\\,\\text{n\u1ebfu}\\,\\,{A}<{0} \\\\\\end{align} \\right.$ ","explain":"<span class='basic_left'>V\u00ec $x < 0\\Rightarrow \\dfrac{3}{x{{y}^{4}}}<0$ n\u00ean $\\left| \\dfrac{3}{x{{y}^{4}}} \\right|=-\\dfrac{3}{x{{y}^{4}}}$ <br\/>Ta c\u00f3:<br\/>$x{{y}^{4}}\\sqrt{\\dfrac{9}{{{x}^{2}}{{y}^{8}}}}=x{{y}^{4}}.\\sqrt{{{\\left( \\dfrac{3}{x{{y}^{4}}} \\right)}^{2}}}=x{{y}^{4}}.\\left| \\dfrac{3}{x{{y}^{4}}} \\right|=x{{y}^{4}}.\\dfrac{-3}{x{{y}^{4}}}=-3$ <br\/><span class='basic_pink'>V\u1eady s\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $-3$ <\/span><\/span>"}]}],"id_ques":512},{"time":24,"part":[{"title":"\u0110i\u1ec1n s\u1ed1 th\u00edch h\u1ee3p v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["18"]]],"list":[{"point":5,"width":40,"content":"","type_input":"","type_check":"","ques":"Gi\u1ea3i ph\u01b0\u01a1ng tr\u00ecnh: $\\sqrt{9}\\sqrt{(x-2)} =12$<br\/> Nghi\u1ec7m c\u1ee7a ph\u01b0\u01a1ng tr\u00ecnh l\u00e0 $x= \\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}$","hint":"\u00c1p d\u1ee5ng quy t\u1eafc nh\u00e2n hai c\u0103n b\u1eadc hai, r\u1ed3i b\u00ecnh ph\u01b0\u01a1ng hai v\u1ebf","explain":"<span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span> <br\/> <b>B\u01b0\u1edbc 1:<\/b> T\u00ecm \u0111i\u1ec1u ki\u1ec7n \u0111\u1ec3 c\u0103n th\u1ee9c c\u00f3 ngh\u0129a.<br\/><b>B\u01b0\u1edbc 2:<\/b> B\u00ecnh ph\u01b0\u01a1ng hai v\u1ebf v\u00e0 gi\u1ea3i ph\u01b0\u01a1ng tr\u00ecnh.<br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/>\u0110i\u1ec1u ki\u1ec7n: $x-2\\ge 0\\Leftrightarrow x\\ge 2$ <br\/> Ta c\u00f3:<br\/>$\\sqrt{9}\\sqrt{(x-2)} =12$<br\/>$\\Leftrightarrow\\sqrt{9(x-2)}=12$<br\/>$\\Leftrightarrow 9(x-2)=144\\,$<br\/>$\\Leftrightarrow x-2=16$<br\/>$\\Leftrightarrow x=18$ (th\u1ecfa m\u00e3n)<br\/>T\u1eadp nghi\u1ec7m c\u1ee7a ph\u01b0\u01a1ng tr\u00ecnh $S=\\{18\\}$<br\/><span class='basic_pink'>V\u1eady s\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $18$ <\/span><\/span> "}]}],"id_ques":513},{"time":24,"part":[{"title":"\u0110i\u1ec1n s\u1ed1 th\u00edch h\u1ee3p v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["4"]]],"list":[{"point":5,"width":40,"content":"","type_input":"","type_check":"","ques":"Gi\u1ea3i ph\u01b0\u01a1ng tr\u00ecnh: $\\sqrt{3x}-\\sqrt{12}= 0$<br\/>Nghi\u1ec7m c\u1ee7a ph\u01b0\u01a1ng tr\u00ecnh l\u00e0 $x= \\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}$","hint":"Chuy\u1ec3n v\u1ebf v\u00e0 b\u00ecnh ph\u01b0\u01a1ng hai v\u1ebf","explain":"<span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span> <br\/> <b>B\u01b0\u1edbc 1:<\/b> T\u00ecm \u0111i\u1ec1u ki\u1ec7n \u0111\u1ec3 c\u0103n th\u1ee9c c\u00f3 ngh\u0129a.<br\/><b>B\u01b0\u1edbc 2:<\/b> Chuy\u1ec3n v\u1ebf v\u00e0 gi\u1ea3i ph\u01b0\u01a1ng tr\u00ecnh.<br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/>\u0110i\u1ec1u ki\u1ec7n: $x\\ge 0$ <br\/> Ta c\u00f3: <br\/>$\\sqrt{3x}-\\sqrt{12}=0$<br\/>$\\Leftrightarrow \\sqrt{3x}=\\sqrt{12}\\,$<br\/>$\\Leftrightarrow 3x=12$<br\/>$\\Leftrightarrow x=4$ (th\u1ecfa m\u00e3n)<br\/>T\u1eadp nghi\u1ec7m c\u1ee7a ph\u01b0\u01a1ng tr\u00ecnh $S=\\{4\\}$ <br\/> <span class='basic_pink'>V\u1eady s\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $4$<\/span><\/span>"}]}],"id_ques":514},{"time":24,"part":[{"title":"Ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang","title_trans":"","temp":"multiple_choice","correct":[[2]],"list":[{"point":5,"select":["A. $\\dfrac{2}{5}a$","B. $\\dfrac{3}{5}a$","C. $-\\dfrac{4}{5}a$"],"ques":"V\u1edbi $a \\ge 0.$ R\u00fat g\u1ecdn bi\u1ec3u th\u1ee9c sau: <br\/>$\\sqrt{\\dfrac{5a}{3}}.\\sqrt{\\dfrac{27a}{125}}=?$","hint":"V\u1edbi hai s\u1ed1 $a$ v\u00e0 $b$ kh\u00f4ng \u00e2m ta c\u00f3: $\\sqrt{a}.\\sqrt{b}=\\sqrt{a.b}$ ","explain":"<span class='basic_left'>V\u00ec $a\\ge0$ n\u00ean $|a|=a$ <br\/>Ta c\u00f3<br\/>$\\sqrt{\\dfrac{5a}{3}}.\\sqrt{\\dfrac{27a}{125}}=\\sqrt{\\dfrac{5a}{3}.\\dfrac{27a}{125}}$$=\\sqrt{\\dfrac{9{{a}^{2}}}{25}}=\\left| \\dfrac{3a}{5} \\right|=\\dfrac{3}{5}|a|=\\dfrac{3a}{5}$ <br\/><br\/><span class='basic_left'> <span class='basic_green'>Nh\u1eadn x\u00e9t:<\/span> <br\/> V\u1edbi hai s\u1ed1 $a$ v\u00e0 $b$ kh\u00f4ng \u00e2m, ta c\u00f3: $\\sqrt{a}.\\sqrt{b}=\\sqrt{a.b}$ <br\/> V\u1edbi m\u1ecdi s\u1ed1 th\u1ef1c $a$, ta c\u00f3 $\\sqrt{a^2}=|a|=\\left\\{ \\begin{align} & a\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\text{n\u1ebfu}\\,\\,\\,\\,\\,\\,\\,\\,{a}\\ge {0} \\\\ & -a\\,\\,\\,\\,\\text{n\u1ebfu}\\,\\,\\,\\,\\,\\,\\,\\,{a}< {0} \\\\\\end{align} \\right.$ <br\/><\/span><\/span>"}]}],"id_ques":515},{"time":24,"part":[{"title":"\u0110i\u1ec1n s\u1ed1 th\u00edch h\u1ee3p v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["2"]]],"list":[{"point":5,"width":40,"content":"","type_input":"","type_check":"","ques":"T\u00ednh gi\u00e1 tr\u1ecb bi\u1ec3u th\u1ee9c: $C= \\sqrt{\\dfrac{{{a}^{2}}-10a+25}{{{b}^{2}}}}\\,\\,$$\\,\\,\\text{t\u1ea1i}\\,\\,\\, a= 1 ; b=2$<br\/>\u0110\u00e1p \u00e1n: $C = $_input_","hint":"\u00c1p d\u1ee5ng: $a^2-2ab+b^2=(a-b)^2$ ","explain":"<span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span> <br\/><b>B\u01b0\u1edbc 1:<\/b> Bi\u1ebfn \u0111\u1ed5i bi\u1ec3u th\u1ee9c trong c\u0103n v\u00e0 r\u00fat g\u1ecdn.<br\/><b>B\u01b0\u1edbc 2:<\/b>Thay gi\u00e1 tr\u1ecb c\u1ee7a $a$ v\u00e0 $b$ v\u00e0o bi\u1ec3u th\u1ee9c \u0111\u00e3 r\u00fat g\u1ecdn. <br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/>Ta c\u00f3:<br\/>$C=\\sqrt{\\dfrac{{{a}^{2}}-10a+25}{{{b}^{2}}}}\\,$$=\\sqrt{\\dfrac{{{\\left( a-5 \\right)}^{2}}}{{{b}^{2}}}}\\,$$=\\left| \\dfrac{a-5}{b} \\right|$ <br\/>Thay $a=1; b=2$ v\u00e0o bi\u1ec3u th\u1ee9c $C$ \u0111\u00e3 r\u00fat g\u1ecdn, ta \u0111\u01b0\u1ee3c: $C=\\left| \\dfrac{1-5}{2} \\right|=\\left| \\dfrac{-4}{2} \\right|=2$<br\/><span class='basic_pink'>V\u1eady s\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $2$ <\/span><br\/><b>Nh\u1eadn x\u00e9t:<\/b> V\u1edbi b\u00e0i to\u00e1n n\u00e0y ta c\u00f3 th\u1ec3 thay tr\u1ef1c ti\u1ebfp gi\u00e1 tr\u1ecb c\u1ee7a $a$ v\u00e0 $b$ v\u00e0o bi\u1ec3u th\u1ee9c $C$ ban \u0111\u1ea7u. <\/span>"}]}],"id_ques":516},{"time":24,"part":[{"title":"\u0110i\u1ec1n s\u1ed1 th\u00edch h\u1ee3p v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["1"]]],"list":[{"point":5,"width":40,"content":"","type_input":"","type_check":"","ques":"T\u00ednh gi\u00e1 tr\u1ecb bi\u1ec3u th\u1ee9c: $A = \\sqrt{(4x^2+4x+1)^2}\\,\\,$$\\,\\,\\text{t\u1ea1i}\\,\\,\\, x= -1$<br\/>\u0110\u00e1p \u00e1n: $A= $_input_","hint":"\u0110\u01b0a bi\u1ec3u th\u1ee9c trong ngo\u1eb7c v\u1ec1 d\u1ea1ng b\u00ecnh ph\u01b0\u01a1ng m\u1ed9t t\u1ed5ng. ","explain":"<span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span> <br\/><b>B\u01b0\u1edbc 1:<\/b> Bi\u1ebfn \u0111\u1ed5i bi\u1ec3u th\u1ee9c trong c\u0103n<br\/><b>B\u01b0\u1edbc 2:<\/b> Khai c\u0103n, t\u00ednh gi\u00e1 tr\u1ecb c\u1ee7a $A$<br\/> <br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/>$A=\\sqrt{{{\\left( 4{{x}^{2}}+4x+1 \\right)}^{2}}}\\,$$=\\sqrt{{{\\left[{{\\left( 2x+1 \\right)}^{2}} \\right]}^{2}}}\\,$$=\\sqrt{{{\\left( 2x+1 \\right)}^{4}}}={{\\left( 2x+1 \\right)}^{2}}$ <br\/>Thay $x=-1$ v\u00e0o bi\u1ec3u th\u1ee9c $A$ \u0111\u00e3 r\u00fat g\u1ecdn, ta \u0111\u01b0\u1ee3c: $A={{\\left[ 2.\\left( -1 \\right)+1 \\right]}^{2}}=1$ <br\/><span class='basic_pink'>V\u1eady s\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $1$ <\/span><\/span>"}]}],"id_ques":517},{"time":24,"part":[{"title":"\u0110i\u1ec1n d\u1ea5u $> ,<, =$ th\u00edch h\u1ee3p v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank_random","correct":[[[">"]]],"list":[{"point":5,"width":40,"content":"","type_input":"","type_check":"","ques":" $\\sqrt{49-25}$ _input_ $\\sqrt{49}-\\sqrt{25}$","hint":"T\u00ednh t\u1eebng v\u1ebf r\u1ed3i so s\u00e1nh ","explain":"<span class='basic_left'>Ta c\u00f3: <br\/>$\\sqrt{49-25}=\\sqrt{24}$;<br\/> $\\sqrt{49}-\\sqrt{25}=7-5=2$<br\/>M\u00e0: $\\sqrt{24} > \\sqrt{4} =2\\Rightarrow \\sqrt{49-25}$ $>$ $\\sqrt{49}-\\sqrt{25}$ <br\/><span class='basic_pink'>V\u1eady d\u1ea5u c\u1ea7n \u0111i\u1ec1n l\u00e0 d\u1ea5u $>$ <\/span><br\/><i>Nh\u1eadn x\u00e9t:<\/i><br\/>V\u1edbi $a \\ge b \\ge 0$, ta c\u00f3 $\\sqrt{a-b} \\ge \\sqrt{a}-\\sqrt{b}$<\/span>"}]}],"id_ques":518},{"time":24,"part":[{"title":"\u0110i\u1ec1n s\u1ed1 th\u00edch h\u1ee3p v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank_random","correct":[[["3"],["7"]]],"list":[{"point":5,"width":30,"content":"","type_input":"","type_check":"","ques":"K\u1ebft qu\u1ea3 r\u00fat g\u1ecdn bi\u1ec3u th\u1ee9c:<br\/>$\\dfrac{\\sqrt{15}-\\sqrt{6}}{\\sqrt{35}-\\sqrt{14}} =\\dfrac{\\sqrt{\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}}}{\\sqrt{\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}}}$ ","hint":"Ph\u00e2n t\u00edch t\u1eed v\u00e0 m\u1eabu th\u00e0nh nh\u00e2n t\u1eed r\u1ed3i r\u00fat g\u1ecdn.","explain":"<span class='basic_left'>Ta c\u00f3: <br\/>$\\dfrac{\\sqrt{15}-\\sqrt{6}}{\\sqrt{35}-\\sqrt{14}}=\\dfrac{\\sqrt {3.5}-\\sqrt{3.2}}{\\sqrt{7.5}-\\sqrt{7.2}}=\\dfrac{\\sqrt{3}\\left( \\sqrt{5}-\\sqrt{2} \\right)}{\\sqrt{7}\\left( \\sqrt{5}-\\sqrt{2} \\right)}\\,$$=\\dfrac{\\sqrt{3}}{\\sqrt{7}}$ <br\/><span class='basic_pink'>V\u1eady \u00f4 tr\u1ed1ng c\u1ea7n \u0111i\u1ec1n l\u00e0 $3$ v\u00e0 $7$<\/span><\/span>"}]}],"id_ques":519},{"time":24,"part":[{"title":"Ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"select":["A. $\\dfrac{4}{7}$","B. $\\dfrac{3}{7}$","C. $-\\dfrac{2}{7}$"],"ques":" T\u00ednh $\\left( \\sqrt{\\dfrac{1}{7}}-\\sqrt{\\dfrac{16}{7}}+\\sqrt{7} \\right):\\sqrt{7}=$ ?","hint":" V\u1edbi s\u1ed1 $a$ kh\u00f4ng \u00e2m v\u00e0 s\u1ed1 $b$ d\u01b0\u01a1ng ta c\u00f3: $\\dfrac{\\sqrt{a}}{\\sqrt{b}}=\\sqrt{\\dfrac{a}{b}}$ ","explain":"<span class='basic_left'>Ta c\u00f3:<br\/>$\\begin{aligned} & \\left( \\sqrt{\\dfrac{1}{7}}-\\sqrt{\\dfrac{16}{7}}+\\sqrt{7} \\right):\\sqrt{7} \\\\ & =\\sqrt{\\dfrac{1}{7}:7}-\\sqrt{\\dfrac{16}{7}:7}+\\sqrt{7:7} \\\\ & =\\sqrt{\\dfrac{1}{49}}-\\sqrt{\\dfrac{16}{49}}+\\sqrt{1} \\\\ & =\\dfrac{1}{7}-\\dfrac{4}{7}+1=\\dfrac{4}{7} \\\\ \\end{aligned}$ <br\/><\/span>"}]}],"id_ques":520},{"time":24,"part":[{"title":"Ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang","title_trans":"","temp":"multiple_choice","correct":[[3]],"list":[{"point":5,"select":["A. $\\dfrac{1}{3}x$","B. $\\dfrac{1}{3}x^2$","C. $\\dfrac{1}{3}x^3$"],"ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop9/toan/daiso/bai3/lv1/img\/2.jpg' \/><\/center>$\\sqrt{3{{x}^{7}}}:\\sqrt{27x}= $ ? v\u1edbi $x > 0$","hint":" V\u1edbi s\u1ed1 $a$ kh\u00f4ng \u00e2m v\u00e0 s\u1ed1 $b$ d\u01b0\u01a1ng ta c\u00f3: $\\dfrac{\\sqrt{a}}{\\sqrt{b}}=\\sqrt{\\dfrac{a}{b}}$ ","explain":"<span class='basic_left'>V\u1edbi $x > 0$ n\u00ean $3x^7>0$ v\u00e0 $27x>0$<br\/>Khi \u0111\u00f3, ta c\u00f3:$\\sqrt{3{{x}^{7}}}:\\sqrt{27x}=\\sqrt{\\dfrac{3{{x}^{7}}}{27x}}$$\\,=\\sqrt{\\dfrac{1}{9}{{x}^{6}}}=\\dfrac{1}{3}{{x}^{3}}$ (v\u00ec $x > 0$ )<br\/><\/span> "}]}],"id_ques":521},{"time":24,"part":[{"title":"Ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"select":["A. $9a^2b^4$","B. $81a^2b^4$","C. $81a^4b^4$"],"ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop9/toan/daiso/bai3/lv1/img\/4.jpg' \/><\/center> $\\sqrt{81{{a}^{4}}{{b}^{8}}}$ =?","hint":" \u00c1p d\u1ee5ng: V\u1edbi m\u1ecdi s\u1ed1 th\u1ef1c $a$, ta c\u00f3 $\\sqrt{a^2}=|a|=\\left\\{ \\begin{align} & a\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\text{n\u1ebfu}\\,\\,\\,\\,\\,\\,\\,\\,{a}\\ge {0} \\\\ & -a\\,\\,\\,\\,\\text{n\u1ebfu}\\,\\,\\,\\,\\,\\,\\,\\,{a}< {0} \\\\\\end{align} \\right.$. ","explain":"<span class='basic_left'>Ta c\u00f3:<br\/>$\\sqrt{81{{a}^{4}}{{b}^{8}}}=\\sqrt{{{\\left( 9{{a}^{2}}{{b}^{4}} \\right)}^{2}}}=9{{a}^{2}}{{b}^{4}}$ <br\/><\/span>"}]}],"id_ques":522},{"time":24,"part":[{"title":"Ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"select":["A. $\\dfrac{3}{4}$","B. $\\dfrac{45}{80}$","C. $\\dfrac{5}{8}$"],"ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop9/toan/daiso/bai3/lv1/img\/1.png' \/><\/center> $\\sqrt{45}:\\sqrt{80} =$ ?","hint":" \u00c1p d\u1ee5ng: V\u1edbi s\u1ed1 $a$ kh\u00f4ng \u00e2m v\u00e0 s\u1ed1 $b$ d\u01b0\u01a1ng ta c\u00f3: $\\dfrac{\\sqrt{a}}{\\sqrt{b}}=\\sqrt{\\dfrac{a}{b}}$","explain":"<span class='basic_left'>Ta c\u00f3:<br\/>$\\sqrt{45}:\\sqrt{80} =\\sqrt{\\dfrac{45}{80}}=\\sqrt{\\dfrac{9}{16}}=\\dfrac{3}{4}$ <br\/><\/span>"}]}],"id_ques":523},{"time":24,"part":[{"title":"\u0110i\u1ec1n s\u1ed1 th\u00edch h\u1ee3p v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["15"]]],"list":[{"point":5,"width":40,"content":"","type_input":"","type_check":"","ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop9/toan/daiso/bai3/lv1/img\/2.jpg' \/><\/center> $\\sqrt{5}.\\sqrt{45}=$_input_ ","hint":"\u00c1p d\u1ee5ng: V\u1edbi hai s\u1ed1 $a$ v\u00e0 $b$ kh\u00f4ng \u00e2m ta c\u00f3: $\\sqrt{a}.\\sqrt{b}=\\sqrt{a.b}$ ","explain":"<span class='basic_left'>Ta c\u00f3: <br\/>$\\sqrt{5}.\\sqrt{45}=\\sqrt{5.45}=\\sqrt{225}=15$ <br\/><span class='basic_pink'>V\u1eady \u00f4 tr\u1ed1ng c\u1ea7n \u0111i\u1ec1n l\u00e0 $15$<\/span><\/span>"}]}],"id_ques":524},{"time":24,"part":[{"title":"\u0110i\u1ec1n v\u00e0o s\u1ed1 th\u00edch h\u1ee3p v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["6"],["13"]]],"list":[{"point":5,"width":40,"content":"","type_input":"","type_check":"","ques":" T\u00ednh: $\\sqrt{\\dfrac{36}{169}}=\\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":"","explain":"<span class='basic_left'>Ta c\u00f3: <br\/>$\\sqrt{\\dfrac{36}{169}}=\\dfrac{\\sqrt{36}}{\\sqrt{169}}=\\dfrac{6}{13}$ <br\/><span class='basic_pink'>V\u1eady \u00f4 tr\u1ed1ng c\u1ea7n \u0111i\u1ec1n l\u00e0 $\\dfrac{6}{13}$ <\/span> <\/span>"}]}],"id_ques":525},{"time":24,"part":[{"title":"\u0110i\u1ec1n s\u1ed1 th\u00edch h\u1ee3p v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["66"]]],"list":[{"point":5,"width":40,"content":"","type_input":"","type_check":"","ques":" T\u00ednh: $\\sqrt{121.36}=$_input_ ","hint":"\u00c1p d\u1ee5ng: V\u1edbi hai s\u1ed1 $a$ v\u00e0 $b$ kh\u00f4ng \u00e2m ta c\u00f3: $\\sqrt{a}.\\sqrt{b}=\\sqrt{a.b}$ ","explain":"<span class='basic_left'>Ta c\u00f3:<br\/>$\\sqrt{121.36}=\\sqrt{121}.\\sqrt{36}=11.6=66$ <br\/><span class='basic_pink'>V\u1eady \u00f4 tr\u1ed1ng c\u1ea7n \u0111i\u1ec1n l\u00e0 $66$<\/span><\/span>"}]}],"id_ques":526},{"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":"K\u1ebft qu\u1ea3 r\u00fat g\u1ecdn $\\dfrac{\\sqrt{2{{x}^{4}}}}{\\sqrt{32{{x}^{6}}}}$ (v\u1edbi $x< 0$) l\u00e0: ","select":["A. $\\dfrac{1}{4x}$","B. $-\\dfrac{1}{2x}$ ","C. $\\dfrac{1}{4|x|}$","D. $-\\dfrac{1}{4x}$"],"hint":"\u00c1p d\u1ee5ng: V\u1edbi s\u1ed1 $a$ kh\u00f4ng \u00e2m v\u00e0 s\u1ed1 $b$ d\u01b0\u01a1ng ta c\u00f3: $\\dfrac{\\sqrt{a}}{\\sqrt{b}}=\\sqrt{\\dfrac{a}{b}}$ ","explain":"<span class='basic_left'>Ta c\u00f3: <br\/>$\\dfrac{\\sqrt{2{{x}^{4}}}}{\\sqrt{32{{x}^{6}}}}=\\sqrt{\\dfrac{2{{x}^{4}}}{32{{x}^{6}}}}=\\sqrt{\\dfrac{1}{16{{x}^{2}}}}$$\\,=\\dfrac{1}{4|x|}=-\\dfrac{1}{4x}$ (v\u00ec $x < 0$)<br\/><span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 D <\/span><br\/><span class='basic_left'><span class='basic_green'>Nh\u1eadn x\u00e9t:<\/span><br\/>+ V\u1edbi s\u1ed1 $a$ kh\u00f4ng \u00e2m v\u00e0 s\u1ed1 $b$ d\u01b0\u01a1ng ta c\u00f3: $\\dfrac{\\sqrt{a}}{\\sqrt{b}}=\\sqrt{\\dfrac{a}{b}}$ <br\/>+ V\u1edbi m\u1ecdi s\u1ed1 th\u1ef1c $a$, ta c\u00f3 $\\sqrt{a^2}=|a|=\\left\\{ \\begin{align} & a\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\text{n\u1ebfu}\\,\\,\\,\\,\\,\\,\\,\\,{a}\\ge {0} \\\\ & -a\\,\\,\\,\\,\\text{n\u1ebfu}\\,\\,\\,\\,\\,\\,\\,\\,{a}< {0} \\\\\\end{align} \\right.$ <br\/><\/span>","column":2}]}],"id_ques":527},{"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":"K\u1ebft qu\u1ea3 r\u00fat g\u1ecdn bi\u1ec3u th\u1ee9c $\\sqrt{10{{m}^{2}}}.\\sqrt{40{{n}^{2}}}$ l\u00e0: ","select":["A. $20mn$","B. $-20mn$ ","C. $20|mn|$","D. $-20|mn|$ "],"hint":"V\u1edbi hai s\u1ed1 $a$ v\u00e0 $b$ kh\u00f4ng \u00e2m ta c\u00f3: $\\sqrt{a}.\\sqrt{b}=\\sqrt{a.b}$ ","explain":"<span class='basic_left'> Ta c\u00f3: $10m^2\u22650\\,\\,\\forall m$ v\u00e0 $40n^2\u22650\\,\\,\\forall n$ n\u00ean <br\/>$\\sqrt{10{{m}^{2}}}.\\sqrt{40{{n}^{2}}}=\\sqrt{10{{m}^{2}}.40.{{n}^{2}}}$$\\,=\\sqrt{{{\\left( 20mn \\right)}^{2}}}=20|mn|$<br\/><span class='basic_pink'>\u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 C <\/span><br\/><span class='basic_left'><span class='basic_green'>Nh\u1eadn x\u00e9t:<\/span><br\/>+ V\u1edbi s\u1ed1 $a$ kh\u00f4ng \u00e2m v\u00e0 s\u1ed1 $b$ d\u01b0\u01a1ng ta c\u00f3: $\\dfrac{\\sqrt{a}}{\\sqrt{b}}=\\sqrt{\\dfrac{a}{b}}$ <br\/>+ V\u1edbi m\u1ecdi s\u1ed1 th\u1ef1c $a$, ta c\u00f3 $\\sqrt{a^2}=|a|=\\left\\{ \\begin{align} & a\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\text{n\u1ebfu}\\,\\,\\,\\,\\,\\,\\,\\,{a}\\ge {0} \\\\ & -a\\,\\,\\,\\,\\text{n\u1ebfu}\\,\\,\\,\\,\\,\\,\\,\\,{a}< {0} \\\\\\end{align} \\right.$. <br\/><\/span>","column":2}]}],"id_ques":528},{"time":24,"part":[{"title":"Kh\u1eb3ng \u0111\u1ecbnh sau \u0110\u00fang hay Sai","title_trans":"","temp":"multiple_choice","correct":[[2]],"list":[{"point":5,"ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop9/toan/daiso/bai3/lv1/img\/1.png' \/><\/center>$\\sqrt{16 + 9}=\\sqrt{16}+\\sqrt{9}$ ","select":["A. \u0110\u00fang","B. Sai "],"hint":"","explain":"<span class='basic_left'>Ta c\u00f3: $\\sqrt{16+9}=\\sqrt 25=5 < 7=3+4=\\sqrt{9}+\\sqrt{16}$<br\/> Kh\u1eb3ng \u0111\u1ecbnh tr\u00ean l\u00e0 sai.<br\/><span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B <\/span> <br\/><i>Nh\u1eadn x\u00e9t:<\/i><br\/>V\u1edbi $a,b \\ge 0$, ta c\u00f3 $\\sqrt{a+b} \\le \\sqrt{a}+\\sqrt{b}$<\/span>","column":2}]}],"id_ques":529},{"time":24,"part":[{"title":"Kh\u1eb3ng \u0111\u1ecbnh sau \u0110\u00fang hay Sai","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop9/toan/daiso/bai3/lv1/img\/2.jpg' \/><\/center>V\u1edbi $A,B \\ge 0$, ta c\u00f3: $\\sqrt{A.B}=\\sqrt{A}.\\sqrt{B}$ ","select":["A. \u0110\u00fang","B. Sai "],"hint":"","explain":"<span class='basic_left'>V\u1edbi hai bi\u1ec3u th\u1ee9c $A, B$ kh\u00f4ng \u00e2m, ta c\u00f3: $\\sqrt{A.B}=\\sqrt{A}.\\sqrt{B}$ <br\/> Kh\u1eb3ng \u0111\u1ecbnh tr\u00ean l\u00e0 \u0111\u00fang. <br\/><span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 A <\/span>","column":2}]}],"id_ques":530}],"lesson":{"save":0,"level":1}}