Giá trị a 2 − 3 log a b (0 < a ≠ 1, b > 0) bằng

A

\({a^{2 - 3{{\log }_a}b}} = \frac{{{a^2}}}{{{a^{3{{\log }_a}b}}}} = \frac{{{a^2}}}{{{b^3}}} = {a^2}{b^{ - 3}}\).