Answer:
6
Step-by-step explanation:
11x^2-8x-14
(2x^2- 8x– 6)+(9x^2-8) = 11x^2-8x-14
12
4*x-9=2x+15
4x-9=2x+15
-2x -2x
2x-9=15
2x=24
x=12