Compute the sum of all integers a for which the polynomial x^2+ax+10a can be factored over the integers.

KitSoundwave Jan 21, 2021

#1**+1 **

All the solutions are

a = 0: x^2 = x*x

a = 40: x^2 + 40x + 400 = (x + 20)(x + 20)

a = 45: x^2 + 45x + 450 = (x + 15)(x + 30)

a = 72: x^2 + 72x + 720 = (x + 12)(x + 60)

0 + 40 + 45 + 72 = 157

Guest Jan 21, 2021

#2**+1 **

Good answer, but what about the negative numbers? I think you're missing some positive numbers as well.

KitSoundwave Jan 22, 2021