# How do you solve the following system using substitution?: 7x+9y=3, x=14-4y

Nov 2, 2015

I found:
$x = - 6$
$y = 5$

#### Explanation:

Take the second equation and substitute it for $x$ into the first getting:
$7 \left(\textcolor{red}{14 - 4 y}\right) + 9 y = 3$ and solve for $y$:
$98 - 28 y + 9 y = 3$
$19 y = 95$
$y = \frac{95}{19} = 5$
substitute this back into the second:
$x = 14 - 4 \left(5\right) = 14 - 20 = - 6$