Factor the polynomial completely

Question

3m^2 -75

This is how I started to work it out.

(3m-23)(m-5)

Answer 1

Start by factoring out the GCF, which in this case is 3.
So you get
3m²-75
=3(m²-25)
The part in parentheses is the difference of two squares. Look up your course notes to see how to factor this part, namely using the standard form:
(A²-B²) = (A+B)(A-B)