Question

How to factor 3n^2+3n-60

Answer 1

$3n^2+3n-60 =\\ 3(n^2+n-20)=\\ 3(n^2+5n-4n-20)=\\ 3(n(n+5)-4(n+5))=\\ 3(n-4)(n+5)$

Answer 2

Factour out the 3 first
3(n^2+n-20)
what 2 numbers muliplty to get -20 and add to get 1
-4 and 5
3(n-4)(n+5)