Вправи 301 - 400 » 342

Спростіть вираз: 1) 7/27m ∙ 9/28n = 7/27 ∙ 9/28 ∙ mn = (1 • 1)/(3 • 4) ∙ mn = 1/12mn; 2) 20x ∙ 11/35y = 20/1 ∙ 11/35 ∙ xy = (4 • 11)/(1 • 7) ∙ xy = 44/7xy = 62/7xy; 3) 34/15x ∙ 117/28y ∙ 4/7z = 49/15x ∙ 45/28y ∙ 4/7z = 49/15 ∙ 45/28 ∙ 4/7 ∙ xyz = 3xyz.