Answer:
47
Step-by-step explanation:
(2x + 3) + (5x - 8) = 72
2x + 3 + 5x - 8 = 72
(2 + 5)x + (3 - 8) = 72
7x - 5 = 72
7x = 72 + 5 = 77
x = 77/7 = 11
BC = 5x - 8 = 5 (11) - 8 = 55 - 8 = 47
To check solution: AB = 2x + 3 = 25, and AB + BC = AC = 72, so 25 + 47 = 72 verifies answer
