2. Реши уравнения и сделай проверку: a) 3-a-7 = 20 (24+ d) : 8 = 7 b:5+8= 17 63: (14-x) = 7 32-16 : n = 30

Решим уравнения и сделаем проверку.

a) 3 ⋅ a - 7 = 20

3 ⋅ a = 20 + 7

3 ⋅ a = 27

a = 27 : 3

a = 9

Проверка:

3 ⋅ 9 - 7 = 20

27 - 7 = 20

20 = 20

Ответ: a = 9

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(24 + d) : 8 = 7

24 + d = 7 ⋅ 8

24 + d = 56

d = 56 - 24

d = 32

Проверка:

(24 + 32) : 8 = 7

56 : 8 = 7

7 = 7

Ответ: d = 32

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b : 5 + 8 = 17

b : 5 = 17 - 8

b : 5 = 9

b = 9 ⋅ 5

b = 45

Проверка:

45 : 5 + 8 = 17

9 + 8 = 17

17 = 17

Ответ: b = 45

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63 : (14 - x) = 7

14 - x = 63 : 7

14 - x = 9

x = 14 - 9

x = 5

Проверка:

63 : (14 - 5) = 7

63 : 9 = 7

7 = 7

Ответ: x = 5

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32 - 16 : n = 30

-16 : n = 30 - 32

-16 : n = -2

n = -16 : (-2)

n = 8

Проверка:

32 - 16 : 8 = 30

32 - 2 = 30

30 = 30

Ответ: n = 8