The answer is..........
A. 9
63 degrees, if that angle is 72 that means the other must be 54 (add to 180), and if that angle on the other triangle is 54, the others must be 63 (add to 180).
2. You simplified parenthesis on both sides
3. Subtracted 14 from -25 on right side
6. Divided each side by 9
4^2 = 16
so x must be greater than 16
answer
E. 17
F. 19