x+ y = 5 2x-y = 4 solve x and y

X = 3 and Y =
2.  Here is how we find this.

What we have to do is use the first equation to
get a value for y.  This is quite easy because all we must do is say

x + y =
5 so y = 5 -x

Now we plug that value into the second equation.

2x - (5-x) = 4

This becomes

2x - 5 + x = 4
(because you are subtracting negative x, you are in effect adding x)

3x - 5 =
4

3x = 9

x = 3

If x = 3, then 3 + y = 5
and y = 2