Question 880270
A negative power is the same as writing one over the power so 

{{{x^-2 = 1/x^2}}}

therefore {{{5x^-2 = 5/x^2}}}

similarly

{{{y^-3 = 1/y^3}}}

so   {{{(y^-3)z^2 = z^2/y^3}}}

Hope this helps.