1. (4х+3)/(3)+4=9х/7
(4х+3+12)/3=9х/7
(4х+15)•7=9х•3
28х+105=27х
28х-27х=-105
Х=-105
2. (Х+5)/(7)+4=Х/3
(Х+5+28)/7=Х/3
(Х+33)•3=7х
3х-7х=-99
-4х=-99
Х=24,75
3. 3х+10=8х/3
(3х+10)•3=8х
9х-8х=-30
Х=-30
4. (6х+7)/(7)+2=9х/8
(6х+7+14)/7=9х/8
(6х+21)•8=9х
48х-9х=-168
39х=-168
Х=-4 целых 12/39
( в последнем не очень уверена)