Question

Упр. 450(3,4,5,6,7,8,9),454,455,456.Помогите, пожалуйста. ​

Answer 1

Ответ:

Пошаговое объяснение:

450.

3)

1целая 7/9 × 15/32 ÷ 1целая 19/36 = 16/9 × 15/32 × 36/55 = (1×3×4)/(1×2×11) = (1×3×2)/(1×1×11)=6/11

4)

1целая 7/9 × (15/32 ÷ 1целая 19/36) = 16/9 × (15/32 × 36/55) = 16/9 × 3/8 × 9/11 = 2/1 × 3/1 × 1/11 = 6/11

5)

3целых 4/7 ÷ 1целая 1/7 × 2/3 = 25/7 × 7/8 × 2/3 = (25×1×1)/(1×4×3) = 25/12 = 2целых 1/12

6)

3целых 4/7 ÷ (1целая 1/7 × 2/3) = 25/7 ÷ (8/7 × 2/3) = 25/7 ÷ 16/21 = 25/7 × 21/16 = 25/1 × 3/16 = 75/16 = 4 целых 11/16

7)

(5/12 + 1/8) ÷ 3/8 = (10/24 + 3/24) × 8/3 = 13/24 × 8/3 = 13/3 × 1/3 = 13/9 = 1целая 4/9

8)

5/12 + 1/8 ÷ 3/8 = 5/12 + 1/8 × 8/3 = 5/12 + 1/3 = 5/12 + 4/12 = 9/12

9)

2целых 6/7 ÷ (5/6 - 9/14) = 20/7 ÷ (35/42 - 27/42) = 20/7 ÷ 8/42 = 20/7 ÷ 4/21 = 20/7 × 21/4 = 5/1 × 3/1 = 15

454.

34целых 2/3 ÷ 8/15 = 104/3 × 15/8 = 13/1 × 5/1 = 65 км/ч скорость поезда

455.

63÷50целых 2/5 = 63 × 5/252 = 1 × 5/4 = 1целая 1/4 часа

1 час = 60 минут

1/4 часа = 60÷4=15 минут

1час и 15 минут время за которое поезд проедет 63 км

456.

3целых 5/9 ÷ 5целых 1/3 = 32/9 × 3/16 = 2/3 × 1/1 = 2/3 кг