Question

Find two consecutive negative integers whose product is 90

Answer 1

-10, -9

Explanation:

Let x = first negative answer

then

x+1 = second negative answer

x(x+1) = 90

x^2 + x = 90

x^2 + x - 90 = 0

(x+10)(x-9) = 0

x = (-10, 9)

Since we're looking for a negative answer, throw out the positive answer leaving:

x = -10 (first negative number)

.

Second negative number"

x+1 = -10+1 = -9