Giải thích các bước giải:
$\begin{array}{l} \left\{ \begin{array}{l} x + my = 3m\\ mx - y = {m^2} + 2 \end{array} \right.\\ \Leftrightarrow \left\{ \begin{array}{l} mx + {m^2}y = 3{m^2}\\ mx - y = {m^2} + 2 \end{array} \right.\\ \Leftrightarrow \left\{ \begin{array}{l} (mx + {m^2}y) - (mx - y) = 3{m^2} - ({m^2} + 2)\\ mx - y = {m^2} + 2 \end{array} \right.\\ \Leftrightarrow \left\{ \begin{array}{l} ({m^2} + 1)y = 2{m^2} - 2\\ mx - y = {m^2} + 2 \end{array} \right.\\ \Leftrightarrow \left\{ \begin{array}{l} y = \frac{{2{m^2} - 2}}{{{m^2} + 1}}\\ mx = {m^2} + 2 + \frac{{2{m^2} - 2}}{{{m^2} + 1}} \end{array} \right.\\ \Leftrightarrow \left\{ \begin{array}{l} y = \frac{{2{m^2} - 2}}{{{m^2} + 1}}\\ x = m + \frac{2}{m} + \frac{{2{m^2} - 2}}{{{m^3} + m}} \end{array} \right. \end{array}$
