Question

How do you find the solution of the system of equations `-x + y = 12` and `x + 2y = 3`?

Answer 1

Try this:
`-x+y=12`
`x+2y=3`
Add the first to the second:
`//+3y=15`
So: `y=5`
Substitute into the first:
`-x+5=12`
`x=-7`