计算：
(1) $(\dfrac{-2a^2b}{3c})^2$；
(2) $(\dfrac{-3x^2y}{2x})^3$；
(3) $\dfrac{4x}{3y} · \dfrac{y}{2x^4} ÷ (\dfrac{1}{x})^2$；
(4) $(-\dfrac{a}{b})^2 ÷ \dfrac{3a}{4b} · \dfrac{2b}{3a}$；
(5) $(\dfrac{-3ac}{2b})^2 ÷ (-9ac^2)$；
(6) $(\dfrac{a^2b}{-c})^3 · (\dfrac{c^2}{-ab})^2 ÷ (\dfrac{bc}{a})^4$；
(7) $(-\dfrac{a}{b})^2 · (-\dfrac{a}{b})^3 ÷ (-a^4b)$；
(8) $(\dfrac{2ab^3}{-c^2d})^2 ÷ \dfrac{6a^2}{b^3} · (\dfrac{-3c}{b^2})^3$；
(9) $6xy^2 ÷ (-\dfrac{3y^2}{2x})^3 · (\dfrac{2y}{3x})^2$；
(10) $(\dfrac{-y^3}{x})^2 · (\dfrac{x}{-y})^3 ÷ (\dfrac{x^2y}{x})^2$；
(11) $(-\dfrac{x}{y})^2 · (-\dfrac{y}{x})^3 ÷ (\dfrac{1}{xy})^2$；
(12) $(\dfrac{a}{b-a})^4 ÷ \dfrac{1}{a^2 - b^2} · (\dfrac{a - b}{ab})^3$。
(1) $(\dfrac{-2a^2b}{3c})^2$；
(2) $(\dfrac{-3x^2y}{2x})^3$；
(3) $\dfrac{4x}{3y} · \dfrac{y}{2x^4} ÷ (\dfrac{1}{x})^2$；
(4) $(-\dfrac{a}{b})^2 ÷ \dfrac{3a}{4b} · \dfrac{2b}{3a}$；
(5) $(\dfrac{-3ac}{2b})^2 ÷ (-9ac^2)$；
(6) $(\dfrac{a^2b}{-c})^3 · (\dfrac{c^2}{-ab})^2 ÷ (\dfrac{bc}{a})^4$；
(7) $(-\dfrac{a}{b})^2 · (-\dfrac{a}{b})^3 ÷ (-a^4b)$；
(8) $(\dfrac{2ab^3}{-c^2d})^2 ÷ \dfrac{6a^2}{b^3} · (\dfrac{-3c}{b^2})^3$；
(9) $6xy^2 ÷ (-\dfrac{3y^2}{2x})^3 · (\dfrac{2y}{3x})^2$；
(10) $(\dfrac{-y^3}{x})^2 · (\dfrac{x}{-y})^3 ÷ (\dfrac{x^2y}{x})^2$；
(11) $(-\dfrac{x}{y})^2 · (-\dfrac{y}{x})^3 ÷ (\dfrac{1}{xy})^2$；
(12) $(\dfrac{a}{b-a})^4 ÷ \dfrac{1}{a^2 - b^2} · (\dfrac{a - b}{ab})^3$。
答案：(1) $\dfrac{4a^4b^2}{9c^2}$
(2) $-\dfrac{27x^3y^3}{8}$
(3) $\dfrac{2}{3x}$
(4) $\dfrac{8}{9}$
(5) $-\dfrac{a}{4b^2}$
(6) $-\dfrac{a^8}{b^3c^3}$
(7) $\dfrac{a}{b^6}$
(8) $-\dfrac{18b^3}{cd^2}$
(9) $-\dfrac{64x^2}{81y^2}$
(10) $-\dfrac{y}{x}$
(11) $-xy^3$
(12) $\dfrac{a^2+ab}{b^3}$
(2) $-\dfrac{27x^3y^3}{8}$
(3) $\dfrac{2}{3x}$
(4) $\dfrac{8}{9}$
(5) $-\dfrac{a}{4b^2}$
(6) $-\dfrac{a^8}{b^3c^3}$
(7) $\dfrac{a}{b^6}$
(8) $-\dfrac{18b^3}{cd^2}$
(9) $-\dfrac{64x^2}{81y^2}$
(10) $-\dfrac{y}{x}$
(11) $-xy^3$
(12) $\dfrac{a^2+ab}{b^3}$