Evaluate the following. Copy down each problem. Simplify your answers. On #$2$ and #$4,$ show your work, use proper notation, and keep things organized.

Hint: #$1$ and #$3$ should help you with #$2$ and #$4.$

$\frac{d}{dx}(\frac{12}{x^2+3})$

${\displaystyle \underset{-1}{\overset{3}{}}}\frac{-24x}{(x^2+3{)}^2}dx$

$\frac{d}{dx}(12ln(x^2+3))$

${\displaystyle \underset{-1}{\overset{3}{}}}\frac{24x}{x^2+3}dx$