a) (-2)⁴ + 3³ = 16 + 27 = 43
б) (-9)² – (-1)⁸ = 81 – 1 = 80
в) 5 × (–$$\frac{2}{5}$$)² = 5 × $$\frac{4}{25}$$ = $$\frac{4}{5}$$ = 0,8