You can put this solution on YOUR website! It may be beneficial to notice that both "end terms" are perfect squares.
So I will venture a guess and say that this function simplifies to (3t+2)^2. Let's foil and make sure.
(3t+2)(3t+2) = 9t^2 + 6t + 6t +4 = 9t^2 +12t +4. Check.
it is.