Đáp án:
c) \(\left\{ \begin{array}{l}
m = 2\\
n = - 5
\end{array} \right.\)
Giải thích các bước giải:
\(\begin{array}{l}
b)Thay:x = 1;y = - 5\\
Hpt \to \left\{ \begin{array}{l}
3m + 5\left( {n + 1} \right) = 93\\
n - 20m = - 3
\end{array} \right.\\
\to \left\{ \begin{array}{l}
n = 20m - 3\\
3m + 5\left( {20m - 3 + 1} \right) = 93
\end{array} \right.\\
\to \left\{ \begin{array}{l}
n = 20m - 3\\
103m = 107
\end{array} \right.\\
\to \left\{ \begin{array}{l}
m = \dfrac{{107}}{{103}}\\
n = \dfrac{{1831}}{{103}}
\end{array} \right.\\
c)Thay:x = 3;y = - 1\\
Hpt \to \left\{ \begin{array}{l}
3\left( {m - 2} \right) - 5n = 25\\
6m + n - 2 = 5
\end{array} \right.\\
\to \left\{ \begin{array}{l}
n = 7 - 6m\\
3m - 6 - 5\left( {7 - 6m} \right) = 25
\end{array} \right.\\
\to \left\{ \begin{array}{l}
n = 7 - 6m\\
33m = 66
\end{array} \right.\\
\to \left\{ \begin{array}{l}
m = 2\\
n = - 5
\end{array} \right.
\end{array}\)
