Question

How do you solve `x-y=4` and `x+y=12`?

Answer 1

`x=8`
`y=4`

Explanation:

first write both equations one above the other so
`x+x=2x`
`-y+y=0`
`12+4=16`
then find x `2x=16`
`x=8`
then use the first equation and find y
`8-y=4`
`-y=-4`
`y=4`