To simplify this, we can re-write the equation
[tex]\frac{10}{-6\text{ }}\text{ x}\frac{x^8}{x^4\text{ }}\text{ x}\frac{y^4}{y^5}[/tex]Appplying laws of indices
[tex]\begin{gathered} \frac{-5}{3}\text{ X x}^{8-4}Xy^{4\text{ - 5}} \\ \frac{-5}{3}x^4y^{-1} \\ \\ \end{gathered}[/tex]This can be expressed as:
[tex]\begin{gathered} \frac{-5}{3}\frac{x^4}{y}^{} \\ \Rightarrow\frac{-5x^4}{3y} \end{gathered}[/tex]