# How do you solve the following system?:  2x+3y=-5 , y=2x+9

May 6, 2018

$x = - 4 , y = 1$

#### Explanation:

1. $2 x + 3 y = - 5$
2. $y = 2 x + 9$

Equation 2 already has $y$ as the subject of the equation, substitute that in place of the $y$ in the first equation.

$2 x + 3 \left(2 x + 9\right) = - 5$

Simplify the equation and calculate the value of $x$.

$2 x + 6 x + 27 = - 5$
$8 x = - 32$
$x = - 4$

Then insert that value of $x$ into equation 2 to find the value of $y$.

$y = 2 \left(- 4\right) + 9$
$y = - 8 + 9$
$y = 1$