which of the following pairs (x,y) is a solution of this system? x + y = 4 -x + 2y = -1

Answer 1

Let's solve this system of equations.

1) x + y = 4
2) -x + 2y = -1

From the first equation, we have x = 4 - y. Substitute this into the second equation:

-(4 - y) + 2y = -1
-4 + y + 2y = -1
3y = 3
y = 1

Substitute y = 1 back into x = 4 - y:
x = 4 - 1
x = 3

Therefore, the solution to the system of equations is (3, 1).