Amy and Stephanie were playing a number game. Amy picked a number and told Stephanie that if she added 9 to the number and multiplied the sum by 3, it would equal 12. Which equation could Stephanie use to find the number, x?
A.
3(x) + 9 = 12

B.
3(x + 9) = 12

C.
3 + (x + 9) = 12

D.
9(x + 3) = 12