Đăng bài 17-05-12 10:29 AM
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Giải các hệ phương trình : $\begin{array}{l} 1)\,\,\,\left\{ \begin{array}{l} {y^2} = {4^x} + 8\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,(1)\\ {2^{x + 1}} + y + 1 = 0\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,(2) \end{array} \right.\\ 2)\,\,\left\{ \begin{array}{l} {y^2} = {4^x} + 2\,\\ {2^{x + 1}} + 2y + 1 = 0 \end{array} \right. \end{array}$
Đăng bài 26-04-12 03:48 PM
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Đăng bài 18-05-12 02:54 PM
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Giải các hệ : $\begin{array}{l} 1)\,\,\,\left\{ \begin{array}{l} {\log _4}x + {\log _4}y = 1 + {\log _4}9\\ x + y - 20 = 0 \end{array} \right.\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,(1)\\ 2)\,\,\left\{ \begin{array}{l} {\log _x}y + {\log _y}x = 2\\ {x^2} - y = 20 \end{array} \right.\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,(2)\\ 3)\,\,\,\left\{ \begin{array}{l} {3^{ - x}}{.2^y} = 1152\\ {\log _{\sqrt 5 }}\left( {x + y} \right) = 2 \end{array} \right.\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,(3) \end{array}$
Đăng bài 26-04-12 04:03 PM
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Đăng bài 31-05-12 08:59 AM
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Đăng bài 19-05-12 10:05 PM
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Đăng bài 14-05-12 08:28 AM
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Đăng bài 12-05-12 12:06 PM
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Đăng bài 14-05-12 01:55 PM
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Đăng bài 27-04-12 08:28 AM
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Giải các hệ phương trình : $\begin{array}{l} 1)\,\,\,\left\{ \begin{array}{l} {\log _{xy}}\left( {x - y} \right) = 1\\ {\log _{xy}}\left( {x + y} \right) = 0 \end{array} \right.\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,(1)\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,3)\,\,\,\left\{ \begin{array}{l} {\log _x}y = 2\\ {\log _{x + 1}}\left( {y + 23} \right) = 3 \end{array} \right.\,\,\,\,\,\,\,\,\,\,\,(3)\\ 2)\,\,\left\{ \begin{array}{l} y = 1 + {\log _4}x\\ {x^y} = 4096 \end{array} \right.\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,(2) \end{array}$
Đăng bài 08-05-12 03:18 PM
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Giải các hệ : $\begin{array}{l} 1)\,\,\,\left\{ \begin{array}{l} x + {2^{y + 1}} = 3\\ 4x + {4^y} = 32 \end{array} \right.\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,3)\,\,\,\left\{ \begin{array}{l} x + {3^{y - 1}} = 2\\ 3x + {9^y} = 18 \end{array} \right.\\ 2)\,\,\left\{ \begin{array}{l} \sqrt y + \log {x^2} = 2\\ y + 4\log x = 28 \end{array} \right.\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,4)\,\,\,\left\{ \begin{array}{l} \sqrt y + 2\log x = 3\\ y - 3\log {x^2} = 1 \end{array} \right. \end{array}$
Đăng bài 26-04-12 04:28 PM
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Giải các hệ : $\begin{array}{l} 1)\,\,\,\,\left\{ \begin{array}{l} {2^{{{\log }_{\frac{1}{2}}}\left( {x + y} \right)}} = {5^{{{\log }_5}\left( {x - y} \right)}}\\ {\log _2}x + {\log _2}y = \frac{1}{2} \end{array} \right.\\ 2)\,\,\,\left\{ \begin{array}{l} {\log _2}xy.{\log _2}\frac{x}{y} = - 3\\ \log _2^2x + \log _2^2y = 5 \end{array} \right.\\ 3)\,\,\,\left\{ \begin{array}{l} {x^2} = 1 + 6{\log _4}x\\ {y^2} = {2^x}.y + {2^{2x + 1}} \end{array} \right.\\ 4)\,\,\,\left\{ \begin{array}{l} {\log _2}x + {\log _4}y + {\log _4}z = 2\\ {\log _3}y + {\log _9}z + {\log _9}x = 2\\ {\log _4}z + {\log _{16}}x + {\log _{16}}y = 2 \end{array} \right. \end{array}$
Đăng bài 08-05-12 03:46 PM
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Giải các hệ : $\begin{array}{l} 1)\,\,\,\left\{ \begin{array}{l} \left( {1 + 2{{\log }_{\left| {xy} \right|}}2} \right).{\log _{x + y}}\left| {xy} \right| = 1\,\,\,\,(1)\\ x - y = 2\sqrt {3\,} \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,(2) \end{array} \right.\\ 2)\,\,\,\left\{ \begin{array}{l} {\log _{\left| {xy} \right|}}\left( {x - y} \right) = 1\\ 2{\log _5}\left| {xy} \right|.{\log _{\left| {xy} \right|}}\left( {x + y} \right) = 1 \end{array} \right. \end{array}$
Đăng bài 08-05-12 03:41 PM
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Giải hệ : $\left\{ \begin{array}{l} {\log _6}\left( {\sqrt x + \sqrt[4] x} \right) = \frac{1}{4}{\log _2}x\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,(1)\\ \frac{{\sin \,\frac{{16\pi }}{x}}+1}{{cos\,\frac{{x\pi }}{{16}}}} < 1 - cos\,\frac{{\sqrt x \pi }}{4}\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,(2) \end{array} \right.$
Đăng bài 27-04-12 08:08 AM
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