a) $$9 \cdot (\frac{5}{6})^2 = 9 \cdot \frac{25}{36} = \frac{9 \cdot 25}{36} = \frac{225}{36} = \frac{25}{4} = 6\frac{1}{4} = 6.25$$
б) $$9 \cdot \frac{5}{6} = \frac{9 \cdot 5}{6} = \frac{45}{6} = \frac{15}{2} = 7\frac{1}{2} = 7.5$$
в) $$(-10)^6 = (-10) \cdot (-10) \cdot (-10) \cdot (-10) \cdot (-10) \cdot (-10) = 1000000$$
г) $$-10^6 = - (10 \cdot 10 \cdot 10 \cdot 10 \cdot 10 \cdot 10) = -1000000$$
Ответ: a) 6.25; б) 7.5; в) 1000000; г) -1000000