Answer:
p^(-9) or 1/p^9
Explanation:
Here we have:
(5p)^(-7)
----------------
(20p)^2
Let's temporarily remove the coefficient 5/20 and reduce it to 1/4.
then we have:
1 1 1
(1/4) ------------- = (1/4) -------------- = ------------
p^7*p^2 p^(7 + 2) p^9