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

Aug 4, 2016

$x = 3$
$y = 2$

#### Explanation:

$x + y = 5$
$2 x - y = 4$
Adding up the above equations we get
$x + 2 x + y - y = 5 + 4$
or
$3 x + 0 = 9$
or
$3 x = 9$
or
$x = \frac{9}{3}$
or
$x = 3$=========Ans $1$
So From equation $x + y = 5$ we get
$3 + y = 5$
or
$y = 5 - 3$
or
$y = 2$=========Ans $2$