I believe the following is your equation:
(6x⁻²y⁵/2z⁻¹¹)⁻³ If so then note that:
6x⁻² = 6/x²
2z⁻¹¹ = 2/z¹¹
Hence (6/x² *2/z¹¹)⁻³ ==>(12)/(x² *z¹¹)⁻³ . The denominator could be written:
(x² *z¹¹)⁻³ = 1/(x² *z¹¹)³ now let's divide the numerator by the denominator:
(12) : 1/(x² *z¹¹)³ => 12 * (x² *z¹¹)³
