Question

3 1/3+(7 1/2-4, 25) :9/20

Answer 1

Решение:

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 1/3 + 7 2/9 = 10/3  +  65/9 = (10×3+65×1)/9=30/9 + 65)9 = 95/9 = 10 5/9

Ответ: 10 5/9.