Question

The product of two consecutive negative integers is 600. What is the value of the lesser integer?

–60
–30
–25
–15

Answer 1

Let the lesser integer be n. Then n(n+1) = 600 → n^2 + n − 600 = 0.
Solve: n = [−1 ± sqrt(1 + 2400)]/2 = [−1 ± 49]/2 → n = 24 or n = −25.
For consecutive negative integers the lesser is −25.