Answer :
[tex]\sqrt\frac{x^6}{y^4}=\frac{\sqrt{x^6}}{\sqrt{y^4}}=\frac{\sqrt{x^{3\cdot2}}}{\sqrt{y^{2\cdot2}}}=\frac{\left(\sqrt{x^2}\right)^3}{\left(\sqrt{y^2}\right)^2}=\frac{|x|^3}{|y|^2}=\frac{|x|^3}{y^2}\\\\\\\\y\neq0[/tex]
