# How do solve the following linear system?:  x + 3y = 9 , y= -2x + 1 ?

May 28, 2018

$x = - \frac{6}{5} , y = \frac{17}{5}$

#### Explanation:

Plugging
$y = - 2 x + 1$ in the first equation we get
$x + 3 \left(- 2 x + 1\right) = 9$
so
$x - 6 x + 3 = 9$
$- 5 x + 3 = 9$
$- 5 x = 6$
$x = - \frac{6}{5}$
so
$y = \frac{12}{5} + \frac{5}{5} = \frac{17}{5}$