For substitution: -2x -2y = 10 y = 4x - 20 6x + 8y = -22 y = -5 (for both plug in the second equation as y in the first equation if that makes sense) (first answer is (3, -8); second answer is (3, -5)
for elimination: 3x + 4y = 2.5 5x - 4y = 25.5 (adding will get you to 8x = 28 bc it gives you 0y; answer is (7/2, -2)) 3x + 4y = 2.84 3x - y = 1.79 (gives you 3y = 1.05 if you subtract; answer is (0.48, 0.35))
