9) Factor completely: 6x2 + 66x + 60
A) 6(x + 1)(x + 10)
B) (6x + 1)(x + 10)
C) 6(x − 1)(x − 10)
D) (6x − 1)(x − 10)

Common Factor 6 out of the terms as you should get 6(x²+11x+10) then factor inside and you get (x+1)(x+10) because

x*x = x² (first)

[x(10)]+[1(x)] = 10x+x = 11x (middle)

10*1 = 10 (last)

So the answer is 6(x+1)(x+10)