# How do you solve 7x+y= 11 and 3x+2y= -11 using substitution?

##### 1 Answer
Mar 30, 2018

$x = 3 \mathmr{and} y = - 10$

#### Explanation:

Rearrange the first equation to get:

$y = 11 - 7 x$

Substitute this into the second equation:

$3 x + 2 \left(11 - 7 x\right) = - 11$

Expand the bracket:

$3 x + 22 - 14 x = - 11$

$22 - 11 x = - 11$

$33 = 11 x$

$x = 3$

Now substitute $x = 3$ into any of the three equations to find $y$:
$y = 11 - 7 x$ $\implies$ $y = 11 - 21$

$y = - 10$