3x + 12
The GCF here is 3.
3x / 3 = x
12 / 3 = 4
So we have 3(x + 4)
7y - 7
The GCF here is 7.
7y / 7 = y
-7 / 7 = -1
So we have 7(y - 1)
5x + 30y
The GCF here is 5.
5x / 5 = x
30y / 5 = 6y
So we have 5(x + 6y)
8m + 36n
The GCF here is 4.
8m / 4 = 2m
36n / 4 = 9n
So we have 4(2m + 9n)