# How do you solve the following system: -2x + 5y = 20, x + y = 4?

Mar 30, 2018

Just arrange the equation. Get $x = 0$ and $y = 4$

#### Explanation:

$- 2 x + 5 y = 20$
$2 x + 2 y = 8$

(after expanding the second equation by 2).

Now combine these equations:

$5 y + 2 y = 20 + 8$

$7 y = 28$

$y = \frac{28}{7}$

$y = 4$

Now put this value into the second equation:

$x + y = 4$

$x = 4 - y$

$x = 4 - 4 = 0$