Answer: -18h^2 + 85h - 18
Step-by-step explanation:
(-2h+9)(9h-2)
Open brackets
(-2h x 9h) + (-2h x -2) + (9 x 9h) + (9 x -2)
-18h^2 + 4h + 81h - 18
Add like terms 4h + 81h
-18h^2 + 85h - 18