Simplify:

(-8x^-6 y^15)^1/3

x ^ - 6 = 1 / x^ 6

third root of ( - 8 ) = - 2

( -8 x ^ - 6 y ^ 15 ) ^ ( 1 /3 ) =

third root of ( - 8 y ^ 15 / x ^ 6 ) =

third root of ( - 8 ) * third root of ( x ^ 15 ) / third root of ( x ^ 6 ) =

- 2 y ^ 5 / x ^ 2