$\noindent For the first one, let $I = \int \frac{3x^{3} - 2}{x^{2} + 4}\, \mathrm{d}x$. Then$
$$\begin{align*}I &= 3\int \frac{x^{3}}{x^{2} + 4}\, \mathrm{d}x - \int \frac{2}{4 + x^{2}}\, \mathrm{d}x \\ \Rightarrow I &= 3\int \frac{x^{3}}{x^{2} + 4}\, \mathrm{d}x - \tan^{-1}...