# How do you solve x=7y+7 and -4x+4y=-16?

Jul 3, 2015

I found:
$x = \frac{7}{2}$
$y = - \frac{1}{2}$

#### Explanation:

You can substitute for $x$ the first equation into the second to get:
$- 4 \left(7 y + 7\right) + 4 y = - 16$
$- 28 y - 28 + 4 y = - 16$
$- 24 y = 12$
$y = \frac{12}{-} 24 = - \frac{1}{2}$
now substitute back into the first equation:
$x = 7 \left(- \frac{1}{2}\right) + 7$
$x = \frac{7}{2}$