Which expression is equivalent to StartFraction b Superscript negative 2 Baseline Over a b Superscript negative 3 Baseline EndFraction? Assume a not-equals 0, b not-equals 0. StartFraction a Over b Superscript 5 Baseline StartFraction 1 Over a b Superscript 5 Baseline Endfraction StartFraction a cubed b Over 1 EndFraction StartFraction b Over a EndFraction.