Answer:
AC = 135 units
Step-by-step explanation:
since PQ bisects AB , then
BC = AC , that is
12x - 21 = 9x + 18 ( subtract 9x from both sides )
3x - 21 = 18 ( add 21 to both sides )
3x = 39 ( divide both sides by 3 )
x = 13
Then
AC = 9x + 18 = 9(13) + 18 = 117 + 18 = 135
