$(1$ point$)$ Find the derivative of the function $g(x)={\displaystyle \underset{6x}{\overset{7x}{}}}\frac{u3}{u^{2}4}du.$

$g^{\text{'}}(x)=$

$$

Hint: : ${\displaystyle \underset{6x}{\overset{7x}{}}}\frac{u3}{u^{2}4}du={\displaystyle \underset{0}{\overset{7x}{}}}\frac{u3}{u^{2}4}du{\displaystyle \underset{6x}{\overset{0}{}}}\frac{u3}{u^{2}4}du$