7. Вычислим:
a) -3,2 : 0,8 = -4
б) -$$\frac{4}{5}$$ * (-$$\frac{5}{16}$$) = $$\frac{4 * 5}{5 * 16}$$ = $$\frac{20}{80}$$ = $$\frac{1}{4}$$ = $$\frac{1}{4}$$
в) (-$$\frac{1}{3}$$)$$^2$$ = (-$$\frac{1}{3}$$) * (-$$\frac{1}{3}$$) = $$\frac{1}{9}$$ = $$\frac{1}{9}$$