# How do you solve x = y + 3 and 2x + y = 9?

May 19, 2016

$x = 4$
$y = 1$

#### Explanation:

Given -

$x = y + 3$ ----------------(1)
$2 x + y = 9$ ----------------(2)

Substitute $x = y + 3$ in equation (2)

$2 \left(y + 3\right) + y = 9$
$2 y + 6 + y = 9$
$3 y + 6 = 9$
$3 y = 9 - 6 = 3$
$y = \frac{3}{3} = 1$
$y = 1$
Substitute $y = 1$ in equation (2)
$x = 1 + 3 = 4$
$x = 4$