Simplify: (a−2b3)−1⋅(a2b−1)2a−3b2\frac{(a^{-2}b^3)^{-1} \cdot (a^2b^{-1})^2}{a^{-3}b^2}a−3b2(a−2b3)−1⋅(a2b−1)2 Which forms are equivalent? (Select all that apply)
a9b−7a^9b^{-7}a9b−7
a9b7\frac{a^9}{b^7}b7a9
a−9b7a^{-9}b^7a−9b7
ab\frac{a}{b}ba