а) \(3^2 + \frac{1}{6}\cdot 4 = 9 + \frac{4}{6} = 9 + \frac{2}{3} = 9\frac{2}{3}\).
б) \(\left(-\frac{2}{7}\right)^5 + \left(-\frac{2}{7}\right)^2 = -\frac{32}{16807} + \frac{4}{49} = -\frac{32}{16807} + \frac{1372}{16807} = \frac{1340}{16807}\).
Ответ: а) \(9\frac{2}{3}\); б) \(\frac{1340}{16807}\).