Answer:
(9p -5q)(9p +5q)
Step-by-step explanation:
The difference of squares is a special form with the factoring ...
... a^2 -b^2 = (a -b)(a +b)
Here, you have ...
so the factoring is ...
... 81p^2 - 25q^2 = (9p -5q)(9p +5q)
