Solve c^2-4c-45=0

Question

What is the answer to c^2-4c-45=0

Answer 1

roblem: Solve c^2-4c-45=0
What is the answer to c^2-4c-45=0

c^2 - 4c - 45 = 0

We are fortunate here, because the factors of
45 are 5 and 9. They just happen to have a
difference of 4. So we factor the left side:

(c - 9)(c + 5) = 0

Setting each factor to zero, we solve for c.

c - 9 = 0
c = 9

and

c + 5 = 0
c = -5

Answer: c = 9  and  c = -5