A rectangle has an area of $\displaystyle{36}{{x}}^{{2}}\usepackage{cmbright}\Huge\$ and a width of $\displaystyle{4}{x}\usepackage{cmbright}\Huge\$ . Find the length of the rectangle using the formula: $\displaystyle\text{Length}=\frac{\text{Area }\ }{\text{Width }\ }\usepackage{cmbright}\Huge\$