# How do you solve the following system:  7x - y = 10 , 8x - y = 13 ?

Jan 6, 2016

$x = 3$ and $y = 11$

#### Explanation:

$7 x - y = 10$$\ldots \ldots \ldots \ldots \ldots . . \left(i\right)$
$8 x - y = 13$$\ldots \ldots \ldots \ldots \ldots \ldots \left(i i\right)$

Subtract $\left(i\right)$ from $\left(i i\right)$
$\implies x = 3$

Put $x = 3$ in $\left(i\right)$
$\implies 7 \left(3\right) - y = 10$
$\implies 21 - y = 10$
$\implies y = 11$
$\implies y = 11$