Question

What are two numbers that multiply to 8 and add up to -9

Answer 1

Explanation:

xy = 8

x + y = -9

Solve with substitution.

y = -x − 9

x (-x − 9) = 8

-x² − 9x = 8

0 = x² + 9x + 8

0 = (x + 1) (x + 8)

x = -1 or -8

y = -8 or -1

The two numbers are -1 and -8.