Question

Which are factors of x2 – 4x – 5? Check all that apply.

1.) (x – 5)
2.) (x – 4)
3.) (x – 2)
4.) (x + 1)
5.) (x + 5)

Answer 1

Ask: Which two numbers add up to -4 and multiply to -5?

-5 and 1

Rewrite the expression using the above

= (x - 5) and (x + 1)