Answer:
5(m-3)
Explanation:
The first step in factoring is to bring out the greatest common factor. In this case, the GCF between 5m and -15 is 5.
To find out out the expression inside the parenthesis, divide the current expression by the GCF,
(5m-15)/5
m-3
Multiply that by the GCF.
5(m-3)