Can someone please help me in solving this problem?

[(1+t)^3 +3(1+t)^2 +2(1+t)] -6

(1+t) -1

So I know the sum a cube gives me (1+t)(1-t+t^2) for the first part of the problem, right?

I am having difficulty with 3(1+t)^2 since I know there is no sum of squares;how am I supposed to factor/multiply this?

Thanks for your help!