Find a pair of integers with a product of -84 and a sum of 5?

Answer 1

Eq1: x*y = -84
Eq2: x+y = 5

x+y = 5
y = 5-x

In Eq1, replace y with 5-x:
x*(5-x) = -84
5x-x^2 = -84
-x^2+5x+84 = 0
Use Quadratic Formula and get:
X = -7, and 12.