а) $$(\frac{3}{4})^2 \cdot 1\frac{1}{3} = \frac{9}{16} \cdot \frac{4}{3} = \frac{36}{48} = \frac{3}{4} = 0.75$$
б) $$3000 \cdot (0,2)^3 - (-2)^6 = 3000 \cdot (0,008) - 64 = 24 - 64 = -40$$
в) $$\frac{1,6}{(0,4)^2} - (-3)^3 = \frac{1,6}{0,16} - (-27) = 10 + 27 = 37$$