Question

Find two numbers who’s product is -9 and who’s sum is -8

Answer 1

1, -9

Explanation:

xy = -9

x + y = -8 solve this for x and substitute into the 1st equation

x = -8 - y

(-8 - y)y = -9

-y² - 8y + 9 = 0

y² + 8y -9 = 0

Solve for y by factoring:

(y - 1)(y + 9) = 0

y = 1, -9

x(1) = -9

x = -9

x(-9) = -9

x = -9/-9 = 1