Hi there,
Take y from first equation and use it / substitute it into the second equation:
-2x + 8 = x - 1, so 3x = 9, therefore x = 3.
Then y = x - 1 = 3 - 1 => y = 2.
Solution is (3,2).
A quick check: 2 = -2*3 + 8, true, and 3 = 2 - 1, also true.
Green eyes.
Here's something I learned, if that's a go math text book the answers are always in the last couple pages of the book