Answer:
48
Step-by-step explanation:
Simple, what you're basically doing is simplifying,

well, you have 3x and you have

12/3=4
and you can "cancel" out an x, making your answer,

.
Answer:
4a^2 + 12ab + 9b^2.
Step-by-step explanation:
Use the identity (a + b)(a + b) = a^2 + 2ab + b^2 :
So
(2a + 3b)(2a + 3b)
= (2a)^2 + 2*(2a)(3b) + (3b)^2
= 4a^2 + 12ab + 9b^2.