Well the first part is 27 but the second part is adding 60 to 21 which is 81. dont forget that!
I think it's C, I could be wrong though
9x + 26 + 7x - 17 = 2x + (-3x) + 5x =
16x + 9 = 2x - 3x + 5x =
16x + 9 = 4x
9 = 4x - 16x
9 = - 12x
-9/12 = x
- 3/4 = x
If you rounded off 129 to the nearest ten the answer would be 130