сначала все преобразовываем потом пишем
а. 21 1/3 = 64/3 = 4³/3
39 1/16 = 625/16 = (5/2)⁴
∛(4³/3)*∛3 *⁴√(5/2)⁴ = 4*5/2 = 10
б. a² - b² = (a - b)(a + b)
1/(⁶√a - ⁶√b) - 1/(⁶√a + ⁶√b) = ((⁶√a + ⁶√b) - (⁶√a - ⁶√b))/ (⁶√a - ⁶√b)*(⁶√a + ⁶√b) = 2*⁶√b/(∛a - ∛b)
2*⁶√b/(∛a - ∛b) * (2*⁶√b/(∛a - ∛b)) = 2*⁶√b
в.
⁴√48 /⁴√3 = ⁴√16 = ⁴√2⁴ = 2
∛- 3 3/8 = ∛ - 27/8 = -∛ (3/2)³ = -3/2
∛-216 / ¹⁰√1024 = - ∛6³ / ¹⁰√2¹⁰ = - 6/2 = -3
2 * (-3/2) : (-3) = 3 * 1/3 = 1
