Answer:
(f+4)(f−5)
Explanation:
The middle number is -1 and the last number is -20.
Factoring means we want something like
(f+_)(f+_)
We need two numbers that...
Add together to get -1
Multiply together to get -20
4+-5 = -1
4*-5 = -20
Fill in the blanks in
(f+_)(f+_)
with 4 and -5 to get...
(f+4)(f-5)