# How do you solve  x+3y=8 and y=2x-9 using substitution?

##### 1 Answer
Mar 6, 2016

I found:
$x = 5$
$y = 1$

#### Explanation:

You can use the second equation substituting it, for $y$, into the second:
$x + 3 \left(\textcolor{red}{2 x - 9}\right) = 8$
$x + 6 x - 27 = 8$
$7 x = 35$
$x = \frac{35}{7} = 5$
We substitute this value of $x$ into the second equation to get:
$y = \left(2 \cdot 5\right) - 9 = 10 - 9 = 1$