Сократите дробь: (42d^2-24d)/(4-7d)^2.

\[\frac{42d^{2} - 24d}{(4 - 7d)^{2}} = \frac{- 6d(4 - 7d)}{(4 - 7d)^{2}} =\]

\[= \frac{- 6d}{4 - 7d} = \frac{6d}{7d - 4}.\]