Question #b895e

1 Answer
Nov 16, 2017

#(x-5)(x+4)#

Explanation:

You need to numbers that add up to the second coefficent (-1) and multiply to get the final constant (-20)

The numbers 4 and -5 work.

So we can rewrite our expression:

#x^2+4x-5x-20#

This is equal to this:

#x(x+4)-5(x+4)#

Which is equal to:

#(x-5)(x+4)#