Toán Giải hpt sau x+x/x-2y=3/2 -y+y/x-2y=1/4 Mn giúp mk giải vs ạ.Mk cảm ơn. 11/09/2021 By Eliza Giải hpt sau x+x/x-2y=3/2 -y+y/x-2y=1/4 Mn giúp mk giải vs ạ.Mk cảm ơn.
Đáp án: $(x,y)=(1;\dfrac{-1}{2})$ Giải thích các bước giải: ĐK: $x\ne 2y$ Ta có: $\begin{array}{l}\left\{ \begin{array}{l}x + \dfrac{x}{{x – 2y}} = \dfrac{3}{2}\\ – y + \dfrac{y}{{x – 2y}} = \dfrac{1}{4}\end{array} \right. \Leftrightarrow \left\{ \begin{array}{l}x + \dfrac{x}{{x – 2y}} = \dfrac{3}{2}\\ – 2y + \dfrac{{2y}}{{x – 2y}} = \dfrac{1}{2}\end{array} \right.\\ \Leftrightarrow \left\{ \begin{array}{l}x + \dfrac{x}{{x – 2y}} = \dfrac{3}{2}\\x + \dfrac{x}{{x – 2y}} – \left( { – 2y + \dfrac{{2y}}{{x – 2y}}} \right) = 1\end{array} \right.\\ \Leftrightarrow \left\{ \begin{array}{l}x + \dfrac{x}{{x – 2y}} = \dfrac{3}{2}\\x + 2y = 0\end{array} \right. \Leftrightarrow \left\{ \begin{array}{l}x = – 2y\\ – 2y + \dfrac{{ – 2y}}{{ – 2y – 2y}} = \dfrac{3}{2}\end{array} \right.\\ \Leftrightarrow \left\{ \begin{array}{l}x = – 2y\\ – 2y + \dfrac{1}{2} = \dfrac{3}{2}\left( {y \ne 0} \right)\end{array} \right. \Leftrightarrow \left\{ \begin{array}{l}x = – 2y\\y = \dfrac{{ – 1}}{2}(tm)\end{array} \right. \Leftrightarrow \left\{ \begin{array}{l}x = 1\\y = \dfrac{{ – 1}}{2}\end{array} \right.\left( {tm} \right)\end{array}$ Vậy hệ có nghiệm duy nhất là: $(x,y)=(1;\dfrac{-1}{2})$ Trả lời
Đáp án: $(x,y)=(1;\dfrac{-1}{2})$
Giải thích các bước giải:
ĐK: $x\ne 2y$
Ta có:
$\begin{array}{l}
\left\{ \begin{array}{l}
x + \dfrac{x}{{x – 2y}} = \dfrac{3}{2}\\
– y + \dfrac{y}{{x – 2y}} = \dfrac{1}{4}
\end{array} \right. \Leftrightarrow \left\{ \begin{array}{l}
x + \dfrac{x}{{x – 2y}} = \dfrac{3}{2}\\
– 2y + \dfrac{{2y}}{{x – 2y}} = \dfrac{1}{2}
\end{array} \right.\\
\Leftrightarrow \left\{ \begin{array}{l}
x + \dfrac{x}{{x – 2y}} = \dfrac{3}{2}\\
x + \dfrac{x}{{x – 2y}} – \left( { – 2y + \dfrac{{2y}}{{x – 2y}}} \right) = 1
\end{array} \right.\\
\Leftrightarrow \left\{ \begin{array}{l}
x + \dfrac{x}{{x – 2y}} = \dfrac{3}{2}\\
x + 2y = 0
\end{array} \right. \Leftrightarrow \left\{ \begin{array}{l}
x = – 2y\\
– 2y + \dfrac{{ – 2y}}{{ – 2y – 2y}} = \dfrac{3}{2}
\end{array} \right.\\
\Leftrightarrow \left\{ \begin{array}{l}
x = – 2y\\
– 2y + \dfrac{1}{2} = \dfrac{3}{2}\left( {y \ne 0} \right)
\end{array} \right. \Leftrightarrow \left\{ \begin{array}{l}
x = – 2y\\
y = \dfrac{{ – 1}}{2}(tm)
\end{array} \right. \Leftrightarrow \left\{ \begin{array}{l}
x = 1\\
y = \dfrac{{ – 1}}{2}
\end{array} \right.\left( {tm} \right)
\end{array}$
Vậy hệ có nghiệm duy nhất là: $(x,y)=(1;\dfrac{-1}{2})$