(3s+4)(3s^(2)-4s-4)
$$(3s+4)(3s^{2}-4s-4)$$
Do you want to expand this?
$$\\(3s+4)(3s^{2}-4s-4)\\\\ = 3s(3s^{2}-4s-4)\;\;+4(3s^{2}-4s-4)$$
can you take it from there?