Вправи 301 - 400 » 389

389. Піднесіть до степеня вираз: 1) (0,4x8y–3)–1 = (4/10)–1x–8y3 = 10/4x–8y3 = 2,5x–8y3; 2) (m–7n–2)–3 = m21n6; 3) (a^5/b^(-2) )–1 = a^(-5)/b^2 = a–5b–2; 4) (〖2a〗^(-6)/b^5 )–3 = (b^5/〖2a〗^(-6) )3 = b^15/〖8a〗^(-18) = 1/8a18b15.