Question

How do you solve the system `x + y = 15` and `x – y = -19`?

Answer 1

`x=-2 and y = 17`

Explanation:

`x + y = 15`
`x - y = -19`
Add both equations, and it will eliminate y and you will get:
`2x + 0y = 15 + (-19)`
`2x = -4`
`x = -4/2`
`x = -2`
Now substitute x = 2 in any equation to find value of y:
`-2 + y = 15`
`y = 15 - (-2)`
`y = 17`
Check the answer:
`-2 + 17 = 15`
`-2 - 17= -19`