\[\frac{\sqrt{a^{10} \cdot b^{20} \cdot c^{30}}}{a^{2}b^{3}c^{4}};\ \ если\ a > 0;\ \ \]
\[c < 0\]
\[\frac{\sqrt{a^{10} \cdot b^{20} \cdot c^{30}}}{a^{2}b^{3}c^{4}} = \frac{- a^{5}b^{10}c^{15}}{a^{2}b^{3}c^{4}} =\]
\[= - a^{3}b^{7}c^{11}\]