# How do you solve the simultaneous equations 2x + y = 12 and x + y = 7?

Jul 15, 2015

$x = 5 , y = 2$

#### Explanation:

Make $y$ the subject in one equation:

$2 x + y = 12$ => $y = 12 - 2 x$

Substitute into the second equation and solve for $x$:

$x + y = 7$ => $x + 12 - 2 x = 7$ => $x = 5$

Use this value to solve for $y$:

$x + y = 7$ => $5 + y = 7$ => $y = 2$