12x - x = 55

2 (x + 3) = 16

5 (x + 3) + 7 = 3 (x + 12)

2 (a + 2) - 10 = 6 (3 - a)

3 (2y - 1) + 6 (3y - 4) = 83 + 5 (y - 3)

1) 12x-x=55

11 х=55

х=55:11

х=5

12*5-5=55

60-5=55

55=55

2) 2 * (x+3) = 16

2 х+6=16

2 х=16-6

2 х=10

х=10:2

х=5

2 * (5+3) = 16

2*8=16

16=16

3) 5 * (x+3) + 7=3 * (x+12)

5 х+15+7=3 х+36

5 х+22=3 х+36

5 х-3 х=36-22

2 х=14

х=14:2

х=7

5 * (7+3) + 7=3 * (7+12)

5*10+7=3*19

57=57

4) 2 * (a+2) - 10=6 * (3-a)

2 а+4-10=18-6 а

2 а+6 а=18-4+10

8 а=24

а=24:8

а=3

2 * (3+2) - 10=6 * (3-3)

2*5-10=6*0

10-10=0

0=0

5) 3 * (2y-1) + 6 * (3y-4) = 83+5 * (y-3)

6 у-3+18 у-24=83+5 у-15

6 у+18 у-5 у=83-15+3+24

19 у=95

у=95:19

у=5

3 * (2*5-1) + 6 * (3*5-4) = 83+5 * (5-3)

3 * (10-1) + 6 * (15-4) = 83+5*2

3*9+6*11=83+10

27+66=93

93=93