giải phương trình $\left \{ {{x=2y-3} \atop {y=2x-3}} \right.$ 31/07/2021 Bởi Audrey giải phương trình $\left \{ {{x=2y-3} \atop {y=2x-3}} \right.$
$\begin{array}{l} \left\{ \begin{array}{l} x = 2y – 3\\ y = 2x – 3 \end{array} \right. \Leftrightarrow \left\{ \begin{array}{l} x – 2y = – 3\\ 2x – y = 3 \end{array} \right.\\ \Leftrightarrow \left\{ \begin{array}{l} 2x – 4y = – 6\\ 2x – y = 3 \end{array} \right. \Leftrightarrow \left\{ \begin{array}{l} – 3y = – 9\\ y = 2x – 3 \end{array} \right.\\ \Leftrightarrow \left\{ \begin{array}{l} x = 3\\ y = 3 \end{array} \right. \to \left( {x;y} \right) = \left( {3;3} \right) \end{array}$ Bình luận
$\begin{array}{l} \left\{ \begin{array}{l} x = 2y – 3\\ y = 2x – 3 \end{array} \right. \Leftrightarrow \left\{ \begin{array}{l} x – 2y = – 3\\ 2x – y = 3 \end{array} \right.\\ \Leftrightarrow \left\{ \begin{array}{l} 2x – 4y = – 6\\ 2x – y = 3 \end{array} \right. \Leftrightarrow \left\{ \begin{array}{l} – 3y = – 9\\ y = 2x – 3 \end{array} \right.\\ \Leftrightarrow \left\{ \begin{array}{l} x = 3\\ y = 3 \end{array} \right. \to \left( {x;y} \right) = \left( {3;3} \right) \end{array}$
Đáp án:
Giải thích các bước giải: