1) 7 1/2 - 4,25 = 7 1/2 - 4 25/100 = 15/2 - 17/4 = (15 × 2 - 17 × 1)/4 = 30/4 - 17/4 = 13/4 = 3 1/4
2)3 1/4 ÷ 9/20 = 13/4 ÷ 9/20 = 13/4 × 20/9 = 65/9 = 7 2/9
3) 3 3/2 + 7 2/9 = 10/3 + 65/9 = (10 × 3 + 65 × 1)/9 = 30/9 + 65)9 = 95/9 = 11 13/18
ОТВЕТ : 11 13/18
Пошаговое объяснение:
