Answer
$\color{blue}{3t^3+5t^2+2t+8}$
Work Step by Step
Distribute each term of the binomial factor to obtain:
$=t(3t^2-t+4)+2(3t^2-t+4$)
Distribute $t$ and $2$ to obtain:
$=t(3t^2)-t(t)+t(4) +2(3t^2)-2(t)+2(4)
\\=3t^3-t^2+4t+6t^2-2t+8$
Combine like terms to obtain:
$=3t^3+(-t^2+6t^2)+(4t-2t)+8
\\=\color{blue}{3t^3+5t^2+2t+8}$