# How do you solve x + y = 4 and x – y = 6?

May 1, 2018

$x = 5 \mathmr{and} y = - 1$

#### Explanation:

We have,

$x + y = 4$

or

$x = 4 - y \text{ } \left(1\right)$

Now, we have

$x - y = 6$

or

$\left(4 - y\right) - y = 6 \text{ }$[from $\left(1\right)$]

or

$4 - 2 y = 6$

$- 2 y = 6 - 4$

$- 2 y = 2$

y= -1#

So

$x + y = 4$

or

$x - 1 = 4$

$x = 4 + 1$

$x = 5$