$\begin{equation*} \begin{cases} y = x - 1 &\\ 5x + 2y = 16 & \end{cases} \end{equation*}$
5x + 2(x − 1) = 16
5x + 2x − 2 = 16
7x = 16 + 2
7x = 18
$x = \frac{18}{7} = 2\frac{4}{7}$
$y = 2\frac{4}{7} - 1 = 1\frac{4}{7}$
Ответ: $x = 2\frac{4}{7}, y = 1\frac{4}{7}$.

$\begin{equation*} \begin{cases} x = 2 - y &\\ 3x - 2y - 11 = 0& \end{cases} \end{equation*}$
3(2 − y) − 2y − 11 = 0
6 − 3y − 2y − 11 = 0
−5y = 11 − 6
−5y = 5
y = −1
x = 2 − (−1) = 2 + 1 = 3
Ответ: x = 3, y = −1.