Пошаговое объяснение:

3) 42 / 14 = 3

80 / 16 = 5

57 / 19 = 3

90 / 45 = 2

82 / 41 = 2

72 / 18 = 4

4) x * (75/5) = 30

75x / 5x = 30

15x = 30

x = 30 / 15

x = 2

Проверка:

2 * (75 / 5) = 30

2 * 15 = 30

30 = 30

x * (88 / 2) = 88

88x / 2x = 88

44x = 88

x = 88 / 44

x = 2

Проверка:

2 * (88 / 2) = 88

2 * 44 = 88

88 = 88

Ответ:

3. 42:14 = 3

90:45 = 2

80:16 = 5

82:41 = 2

57:19 = 3

72:18 = 4

4. X × (75:5) = 30

X = 2

X × (88:2) = 88

X = 2