12х-х=55

11х=55

х=55:11

х=5

Ответ:5

2(х+3)=16

2х+6=16

2х=16-6

2х=10

х=10:2

х=5

Ответ:5

5х+5*3+7=3х+3*12

5х+15+7=3х+36

5х-3х=36-15-7

2х=14

х=14:2

х=7

Ответ:7

5х+15+7=3х+36

5х-3х=36-15-7

2х=14

х=14:2

х=7

Ответ:7

2(а+2)-10=6(3-а)

2а+4-10=18-6а

2а+6а=18-4+10

8а=24

а=24:8

а=3

Ответ:3

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

6у-3+18у-24=83+5у-15

6у+18у-5у=83-15+3-24

19у=95

у=95:19

у=5

Ответ:5

12х - х=55      2  х (х +3)=16       5х + 5 х 3 + 7= 3х + 3 х12      2 х (а +2) -10=6 х (3- а)

11х =55           2х +6=16               5х + 15  + 7 = 3х + 36            2а + 4 -10=18-6а

х=55:11           2х=16-6                  5х + 22= 3х +36                        2а - 6=18 -6а

х=5                   2х=10                      5х - 3х =36 -22                          2а  +6а=18 +6

                             х=10 :2                 2х=14                                          8а=24

                               х=5                     х= 14 : 2                                       а=24 :8

                                                            х=7                                             а=3

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

6у - 3 + 18у -24 = 83 +5у -15

24у -27=68 +5у

24у -5у=68 + 27

19у =95

у=95 : 19

у=5