Question

Solve the following system of equations using the elimination method.
2x + y = 3.5, -x + 2y = 2.5
(__, __)

Answer 1

Start with
2x + y = 3.5
-x + 2y = 2.5

Multiply the second equation by 2: -2x + 4y = 5.
Add this to the first equation to eliminate x:
(2x - 2x) + (y + 4y) = 3.5 + 5 → 5y = 8.5 → y = 1.7 (17/10).

Substitute y into 2x + y = 3.5:
2x + 1.7 = 3.5 → 2x = 1.8 → x = 0.9 (9/10).

Solution: (0.9, 1.7) or (9/10, 17/10).