Решите уравнение:

2 (x+5) = 12

84: (x-3) = 42

3 (x+4) = 33

45: (x-5) = 15

4 (x-7) = 12

1) 2 (х+5) = 12

х+5=12:2

х+5=6

х=6-5

х=1

2 (1+5) = 12

2) 84: (х-3) = 42

х-3=84:42

х-3=2

х=2+3

х=5

84: (5-3) = 42

3) 3 (х+4) = 33

х+4=33:3

х+4=11

х=11-4

х=7

3 (7+4) = 33

4) 45: (х-5) = 15

х-5=45:15

х-5=3

х=3+5

х=8

45: (8-5) = 15

4) 4 (х-7) = 12

х-7=12:4

х-7=3

х=3+7

х10

4 (10-7) = 12