rearrange the equation to where you set it equal to 0 by moving the 25 over.
n2 - 8n -9 = 0
now factor
(n-9)(n+1)
so n1 = 9
n2 = -1
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
From the question we can deduce the formula to be 16 + 3n = 76
3n - 76 - 16
3n = 60
n = 20
20 is the answer.
60, 60 and 60 degrees
There are two criteria: the angles have to all be equal and they have to add up to 180 degrees. This answer satisfies both criteria.