8. Выполнить действия: а) ¹³/₅₅ ⋅ ³³/₃₉; б) 8³/₄ : ⁷/₈.

Решение:

а) ¹³/₅₅ ⋅ ³³/₃₉ = (13 ⋅ 33) / (55 ⋅ 39) = (13 ⋅ 3 ⋅ 11) / (5 ⋅ 11 ⋅ 3 ⋅ 13) = 1/5

б) 8³/₄ : ⁷/₈ = ³⁵/₄ : ⁷/₈ = ³⁵/₄ ⋅ ⁸/₇ = (35 ⋅ 8) / (4 ⋅ 7) = (5 ⋅ 7 ⋅ 4 ⋅ 2) / (4 ⋅ 7) = 5 ⋅ 2 = 10

Ответ: а) 1/5; б) 10