Simplify: a−3b2a2b−4\frac{a^{-3}b^2}{a^2b^{-4}}a2b−4a−3b2
b6a5\frac{b^6}{a^5}a5b6
b−2a\frac{b^{-2}}{a}ab−2
a−5b6a^{-5}b^6a−5b6
a5b6\frac{a^5}{b^6}b6a5