# How do you solve y=1/2x+4 and y=-4x-5 using substitution?

Jul 21, 2016

$x = - 2$
$y = 3$

#### Explanation:

$y = \frac{x}{2} + 4 \mathmr{and} y = - 4 x - 5$
so
$\frac{x}{2} + 4 = - 4 x - 5$
or
$4 x + \frac{x}{2} = - 5 - 4$
or
$9 \frac{x}{2} = - 9$
or
$x = - 2$
Substituting the value of x in the equation $y = \frac{x}{2} + 4$
we get
$y = - \frac{2}{2} + 4$ =$3$