Question 138889
(4^2 x^3 y^2 z^-3 /x^-5 y^8 z^-9)^2 

[16 x^3 y^2 / z^3) / (y^8 / x^5*z^9)]^2

Within the brackets, invert the denominator and multiply.

[16*x^3*y^2*x^5*z^9 / z^3*y^8]^2

[16*x^8*y^3*z^9 / z^3*y^8]^2

[16 x^8 z^6 / y^5]^2

= [256 x^16 z^12 / y^10]

Cheers,
Stan H.