Найдите значение дроби: (6a^2-3ab)/(8ab-4b^2) при a=1/2; b=1/4.

\[\frac{6a^{2} - 3ab}{8ab - 4b^{2}} = \frac{3a(2a - b)}{4b(2a - b)} =\]

\[= \frac{3a}{4b}\]

\[a = \frac{1}{2};\ \ b = \frac{1}{4}:\]

\[\frac{3a}{4b} = \frac{3 \cdot \frac{1}{2}}{4 \cdot \frac{1}{4}} = 1,5.\]