For 20-21, B is the midpoint of AC.
20. A 2x - 8 B x + 17 C X = BC= AB= AC =

Answer:
x = 25
Step-by-step explanation:
since b is the midpoint, 2x - 8 = x + 17
2x - 8 + 8 = x + 17 + 8
2x = x + 25
x = 25
AB = 42
BC = 42
AC = 84