б) (47*1/26)*13/27;(20*1/26)*13/27;. в)(1/2*3/4)*(2/3)*(5/6*7/8)*(6/7*8/9);

б) (47×¹/₂₆)×¹³/₂₇ = ⁴⁷/₂₆ × ¹³/₂₇ = ⁴⁷ˣ¹³/₂₆ₓ₂₇ = ⁴⁷/₂ₓ₂₇ = ⁴⁷/₅₄(20×¹/₂₆)×¹³/₂₇ =  ²⁰/₂₆×¹³/₂₇ = ²⁰ˣ¹³/₂₆ₓ₂₇ = ²⁰/₂ₓ₂₇ = ²⁰/₅₄ = ¹⁰/₂₇в)(1/2×3/4)×(2/3)×(5/6×7/8)×(6/7×8/9) = 2,51/2 × 3/4 = 3/83/8 × 2/3 = 2/8 = 1/45/6 × 7/8 = 35/481/4 × 35/48 = 140/48 = 35/126/7 × 8/9 = 54/6335/12 × 54/63 = 5/2 = 2,5