Solve the following arithmetic problems: 1) 720 - 580 · 5 : 7 + 900 2) 56 : 7 · 125 - 170 + 10 3) 15 + 75 · 5 : 10 - 45 4) 90 · 20 + 1200 : 30 - 53

Решение:

Задание 1:

1. \( 720 - 580 = 140 \)
2. \( 140 \times 5 = 700 \)
3. \( 700 : 7 = 100 \)
4. \( 100 + 900 = 1000 \)

Задание 2:

1. \( 56 : 7 = 8 \)
2. \( 8 \times 125 = 1000 \)
3. \( 1000 - 170 = 830 \)
4. \( 830 + 10 = 840 \)

Задание 3:

1. \( 15 + 75 = 90 \)
2. \( 90 \times 5 = 450 \)
3. \( 450 : 10 = 45 \)
4. \( 45 - 45 = 0 \)

Задание 4:

1. \( 90 \times 20 = 1800 \)
2. \( 1800 + 1200 = 3000 \)
3. \( 3000 : 30 = 100 \)
4. \( 100 - 53 = 47 \)

Ответ: 1) 1000, 2) 840, 3) 0, 4) 47.