Вправи 301 - 400 » 337

Знайдіть значення виразу: 1) 42/3 ∙ 6 – 123/42 ∙ 31/13 + 21/8 ∙ 129/51 = 14/3 ∙ 6 – 65/42 ∙ 40/13 + 17/8 ∙ 80/51 = 28 – 5/21 ∙ 20/1 + 1/1 ∙ 10/3 = 28 – 100/21 + 10/3 = 28 – 416/21 + 31/3 = 26 + 21/21 – 16/21 + 7/21 = 2612/21 = 264/7; 2) (5/12 + 13/20)2 ∙ 113/32 = ((5 • 5 + 13 • 3)/60)2 ∙ 113/32 = (64/60)2 ∙ 45/32 = (16/15)2 ∙ 45/32 = 16/15 ∙ 16/15 ∙ 45/32 = 1/1 ∙ 16/15 ∙ 45/32 = 1/1 ∙ 16/15 ∙ 3/2 = 8/5 = 13/5.