Question

How do you solve the system using elimination `x + y = 5` and `x - y = -1`?

Answer 1

We are going to combine the 2 equations :
`x+y-(x-y)=5-(-1)`
`x+y-x+y=5+1`
`2y=6`
`y=3` ( we divide by `2` on each side )

Now that we have `y`, we can find `x` :

`x+y=5`
`x+3=5`
`x=5-3` ( we substract `3` on each side )
`x=2`