Answer:
c = 0
Explanation:
There can only be one possibility to make this equation make sense. If we were to do any number greater than 0, the equation wouldn't work.
If c = 0
9(0) + 27 = 27
0 + 27 = 27
27 = 27 :)
If c = 1
9(1) + 27 = 27
9 + 27 = 27
36 ≠ 27 :(