Выполните деление: (11a^5b^12)/(12cd^6)∶(55a^3b^2)/(18c^7d^4)∶(21b^6d^2)/(20a^7c^3).

\[\frac{11a^{5}b^{12}}{12cd^{6}}\ :\frac{55a^{3}b^{2}}{18c^{7}d^{4}}\ :\frac{21b^{6}d^{2}}{20a^{7}c^{3}} =\]

\[= \frac{11a^{5}b^{12} \cdot 18c^{7}d^{4} \cdot 20a^{7}c^{3}}{12cd^{6} \cdot 55a^{3}b^{2} \cdot 21b^{6}d^{2}} =\]

\[= \frac{a^{2} \cdot b^{4} \cdot 2 \cdot c^{7} \cdot a^{7} \cdot c^{2}}{d^{2} \cdot 7 \cdot d^{2}} =\]

\[= \frac{2a^{9}b^{4}c^{9}}{7d^{4}}\]