5. Реши уравнения. 30 – x = 20 x + 1 = 40 y – 8 = 7

1. 30 – x = 20

x = 30 - 20

x = 10

Проверка:

30 - 10 = 20

20 = 20

1. x + 1 = 40

x = 40 - 1

x = 39

Проверка:

39 + 1 = 40

40 = 40

1. y – 8 = 7

y = 7 + 8

y = 15

Проверка:

15 - 8 = 7

7 = 7

Ответ: x = 10, x = 39, y = 15