Simplify [(4x^2)^-1 / (-2x^-2)^-3]^-2

(4x^2)^-1 = 1/4x^2

(-2x^-2)^-3 = (-2)^-3 * x^6 = -x^6/8

(1/4x^2) / (-x^6/8) = -8/4x^8 = -2/x^8

(-2/x^8)^-2 = x^16/4