What is x+y=13 x-y=5 solve for the systems of equation in Algebra 1

Add the 2 equations .
(x+y) + (x - y) = 13 + 5
2x=18
therefore x = 9
substituting this answer to the 2nd equation you take ,
y=4

you can also take the value of y , by substituting the value x to the 1st equation. then also you take , y=4 !

1)1 1 = 13
2)1 -1 = 5

Add or subtract the equations together

1) + 2) = 2 + 0 = 18

2x = 18
x = 9

Simply plug into either equation
** excuse me, i made a slight error on this part ***
1) 9 - y = 5
- y = -4
y = 4

Put them underneath eachother and add them. You will see that it says y-y so they cancel out.
Then you add the rest and you get 2y=18
Divide by two on both sides and you get y=9
Then plug 9 into the first equation and solve for x.
x will equal 4.

Add them together; y cancels out, and you are left with 2y = 18, or y = 9.

Plug y into the first eq; x = 4.