Answer:
The square would be 25p^2 - 90p + 81
Step-by-step explanation:
To get this, use the FOIL method. In this, we multiply the first, outer, inner and last pairings.
First - Multiply the first number in each parenthesis.
5p * 5p = 25p^2
Outer - Multiply the outside numbers in each parenthesis.
5p * -9 = -45p
Inner - Multiply the inner numbers in each parenthesis.
-9 * 5p = -45p
Last = Multiply the last numbers in each parenthesis
-9 * -9 = 81
Now take all of those numbers and add together. Then simplify.
25p^2 - 45p - 45p + 81
25p^2 - 90p + 81