Correct. Factor the coefficient 4 into $\displaystyle{2}\cdot{2}\usepackage{cmbright}\Huge\$ : $\displaystyle\sqrt{{{2}\cdot{2}\cdot{{x}}^{{8}}}}\usepackage{cmbright}\Huge\$

Factor the variable into squares: $\displaystyle\sqrt{{{2}\cdot{2}\cdot{{x}}^{{2}}\cdot{{x}}^{{2}}\cdot{{x}}^{{2}}\cdot{{x}}^{{2}}}}\usepackage{cmbright}\Huge\$

Write $\displaystyle{2}\cdot{2}\usepackage{cmbright}\Huge\$ as $\displaystyle{{2}}^{{2}}\usepackage{cmbright}\Huge\$ and separate into individual radicals: $\displaystyle\sqrt{{{{2}}^{{2}}}}\cdot\sqrt{{{{x}}^{{2}}}}\cdot\sqrt{{{{x}}^{{2}}}}\cdot\sqrt{{{{x}}^{{2}}}}\cdot\sqrt{{{{x}}^{{2}}}}\usepackage{cmbright}\Huge\$

Simplify: $\displaystyle{2}\cdot{\left|{x}\right|}\cdot{\left|{x}\right|}\cdot{\left|{x}\right|}\cdot{\left|{x}\right|}={2}{{x}}^{{4}}\usepackage{cmbright}\Huge\$