(3xy^-2)^-4*9x^5/ /x^-5y
(3xy⁻²)⁻⁴ * 9x⁵ = 3⁻⁴ x⁻⁴ y⁸ * 3² x⁵ x⁵ y⁻¹ = 3⁻⁴⁺² x⁻⁴⁺⁵⁺⁵ y⁸⁻¹ = x⁻⁵y = 3⁻² x⁶y⁷ = x⁶y⁷ 9