=-12y-24
Both can be divided by -12, so factor out -12 from each. Your goal is to find the highest common factor in each.
=-12(y+2)
To check your answer distribute the number factored out into (y+2):
=(-12*y) +(-12*2)
=-12y-24 back to original equation
So your answer is: -12(y+2)
Hope this helps!! :)