Ответ:

Пошаговое объяснение:

а)

2 × 1целая 5/12 + 4 × 1целая 1/8 + 1целая 1/9 × 1целая 1/4 = 8целых 13/18

1) 2 × 1целая 5/12 = 2 × 17/12 = 1 × 17/6 = 17/6 = 2целых 5/6

2) 4 × 1целая 1/8 = 4 × 9/8 = 1 × 9/2 = 9/2 = 4целых 1/2

3) 1целая 1/9 × 1целая 1/4 = 10/9 × 5/4 = 5/9 × 5/2 = 25/18 = 1целая 7/18

4) 2целых 5/6 + 4целых 1/2 + 1целая 7/18 = 2целых 15/18 + 4целых 9/18 + 1целая 7/18 = 7целых 31/18 = 8целых 13/18

б)

70 ÷ (5/8 + 5/6) + (3целых 1/9 × 1/3) = 49целых 1/27

1) 3целых 1/9 × 1/3 = 28/9 × 1/3 = 28/27

2) 5/8 + 5/6 = 15/24 + 20/24 = 35/24 = 1целая 11/24

3) 70 ÷ 1целая 11/24 = 70 × 24/35 = 2 × 24/1 = 48

4) 48 + 28/27 = 48целых 28/27 = 49целых 1/27

в)

(1/6 + 1/10 + 1/15) ÷ (3/5 - 1/3 - 1/4) = 20

1) 1/6 + 1/10 + 1/15 = 5/30 + 3/30 + 2/30 = 10/30 = 1/3

2) 3/5 - 1/3 - 1/4 = 36/60 - 20/60 - 15/60 = 1/60

3) 1/3 ÷ 1/60 = 1/3 × 60/1 = 1/1 × 20/1 = 20

г)

(3 - 1целая 5/8) × (4 - 1целая 3/11) ÷ (5 - 1целая 1/4) = 1

1) 3 - 1целая 5/8 = 2целых 8/8 - 1целая 5/8 = 1целая 3/8

2) 4 - 1целая 3/11 = 3целых 11/11 - 1целая 3/11 = 2целых 8/11

3) 5 - 1целая 1/4 = 4целых 4/4 - 1целая 1/4 = 3целых 3/4

4) 1целая 3/8 × 2целых 8/11 = 11/8 × 30/11 = 1/4 × 15/1 = 15/4

5) 15/4 ÷ 3целых 3/4 = 15/4 ÷ 15/4 = 15/4 × 4/15 = 1/1 × 1/1 = 1