you have to use the sum of cubes formula
a3 + b3 = (a+b)(a2 - ab + b2) to factor that.
the 1st thing that is cubed is t so that is going to be the a in the formula and the 2nd thing being cubed is 6 so that is your b in the formula so then you just need to plug it in.
(t+6)(t2 - t*6 + 62) then simplify and you get
(t+6)(t2 - 6t + 36)