Question

по действиям, 12 и 13

Answer 1

Пошаговое объяснение:

№12

1) 2. 7/15 + 1. 7/12 = 2. 28/60 + 1. 35/60 = 3. 63/60 = 4. 3/60 = 4. 1/20

2) 4. 1/20 * 1. 1/9 = 81/20 * 10/9 = 9/2 *1/1 = 9/2 = 4. 1/2

3) 4. 1/2 - 1. 7/8 = 4. 4/8 - 1. 7/8 = 3. 12/8 - 1. 7/8 = 2. 5/8

№13

1) 3. 3/5 * 5/12 = 18/5 * 5/12 = 3/1 * 1/2 = 3/2 = 1. 1/2

2) 4. 3/10 - 1. 1/2 = 4. 3/10 - 1. 5/10 = 3. 13/10 - 1. 5/10 = 2. 8/10 = 2. 4/5

3) 2. 4/5 * 5/6 = 14/5 * 5/6 = 7/1 * 1/3 = 7/3 = 2. 1/3