1. Найдите значение выражения (9a²-16b²) : (3a-4b) при a=²/₃ и b=-¹/₁₂

\[\begin{aligned} \frac{9a^2 - \frac{1}{16b^2}}{3a - \frac{1}{4b}} &= \frac{(3a - \frac{1}{4b})(3a + \frac{1}{4b})}{3a - \frac{1}{4b}} \\ &= 3a + \frac{1}{4b} \end{aligned}\]

\[\begin{aligned} 3a + \frac{1}{4b} &= 3 \cdot \frac{2}{3} + \frac{1}{4 \cdot (-\frac{1}{12})} \\ &= 2 + \frac{1}{-\frac{1}{3}} \\ &= 2 - 3 \\ &= -1 \end{aligned}\]