1. g/h(n) = (n^2 - 2n) / (3n+2)
If this form is fine, this is the final answer. But if you need to divide, then we divide each term in the numerator by 3n+2:
= n/3 - [8n/3 / (3n+2)]
= n/3 - 8/9 + 16/9(3n+2)
= n/3 - 8/9 + 16/(27n+18)
2. g(x) = 2x^3 - x
h(x) = 4x
If that's a multiplication dot:
(g.h)(x) = (2x^3 - x)(4x) = 8x^4 - 4x^2
But if that's a hollow composition dot:
(g of h)(x) = 2(4x)^3 - (4x) = 128x^3 - 4x