AC=11, AB=2x+22 and BC=x+19. find AB

Question

My answer doesn't match the answers on the paper. I have a test on this soon..

Answer 1

Problem: AC=11, AB=2x+22 and BC=x+19. find AB

Given: AB + BC = AC

(2x + 22) + (x + 19) = 11

3x = 11 - 22 -19

3x = -30

x = -10

so AB = 2x + 22 = 2*(-10) + 22 = 2

and BC = x + 19 = -10 + 19 = 9

check: AB + BC = 2 + 9 = 11