Answer:
31cm
Explanation:
Add AC and BC together to get AB.
AC = 2x - 13 and
BC = 3x + 4 and
AB = 36 (this is all the given information)
The two smaller pieces can be combined to equal the whole segment.
AC + BC = AB
2x - 13 + 3x + 4 = 36
combine like terms.
5x - 9 = 36
Add 9
5x = 45
Divide by 5.
x = 9
But you're not done because they asked for BC.
BC = 3x + 4
substitute 9 for x.
BC = 3(9) + 4
BC = 27 + 4
BC = 31
BC is 31 cm.