Answer
$9t^{4}-3t^{2}+11t+12$
Work Step by Step
Subtract vertically.
Line up like terms.
$\begin{array}{lllll}
9t^{4} & & +5t & +8 & \\
& 3t^{2} & -6t & -4 & \\
-- & -- & -- & -- & subtract\\
9t^{4} & 3t^{2} & 11t & 12 &
\end{array}$
Answer: $9t^{4}-3t^{2}+11t+12$
