Answer: -4(3y+4)
Explanation:
First I found the Great common divisor (-4) and took that number and divided -12y and -16 with it getting 3y and 4 and then I set it up as if I was trying to get -12y and -16 so the best way to do that is to use the distributive property so I put 3y and 4 in parentheses like this (3y+4) then I added the -4 on to get the answer of -4(3y+4)