Answer:

Step-by-step explanation:
We can rewrite the question as (x-5)*(x-5).
Using the FOIL Method (First, Outside, Inside, Last):

This simplifies to 
If your looking for the sum, it would be -5 :)
Gina saw 25 monkeys
25 ÷ 5 = 5
5 + 7 = 12
12 + 6 = 18
25 + 5 +12 + 6 = 48 animals
gina saw 48 animals at the zoo
Sum of all the interior angles = (5-2)x180 = 540°
540 - 100 - 120 - 100 - 90 = 130°
So the last unknown angle in the polygon is 130°
Sum of all the adjacent angles on a straight line is 180°
Angle 1 = 180 - 130 = 50°