$\begin{equation*} \begin{cases} y = 7x - 1 &\\ y = 2x & \end{cases} \end{equation*}$
7x − 1 = 2x
7x − 2x = 1
5x = 1
$x = \frac{1}{5}$
$y = 2x = 2 * \frac{1}{5} = \frac{2}{5}$
$\begin{equation*} \begin{cases} x = \frac{1}{5} &\\ y = \frac{2}{5} & \end{cases} \end{equation*}$
Точка пересечения $(\frac{1}{5};\frac{2}{5})$

$\begin{equation*} \begin{cases} y = 3x - 11 &\\ y = 4 & \end{cases} \end{equation*}$
3x − 11 = 4
3x = 4 + 11
3x = 15
x = 5
$\begin{equation*} \begin{cases} x = 5 &\\ y = 4 & \end{cases} \end{equation*}$
Точка пересечения (5;4)

$\begin{equation*} \begin{cases} y = 5x + 8 &\\ y = 3x + 2 & \end{cases} \end{equation*}$
5x + 8 = 3x + 2
5x − 3x = 2 − 8
2x = −6
x = −3
y = 3x + 2 = 3 * (−3) + 2 = −9 + 2 = −7
$\begin{equation*} \begin{cases} x = -3 &\\ y = -7 & \end{cases} \end{equation*}$
Точка пересечения (−3;−7)

$\begin{equation*} \begin{cases} y = 4 - x &\\ y = 3x & \end{cases} \end{equation*}$
4 − x = 3x
3x + x = 4
4x = 4
x = 1
y = 3x = 3 * 1 = 3
$\begin{equation*} \begin{cases} x = 1 &\\ y = 3 & \end{cases} \end{equation*}$
Точка пересечения (1;3)