1)12*3/4+3/4y=y/2-10*1/28
9+3/4y=y/2-5/14
3/4y-1/2y=-9-5/14
1/4y=-131/14
y=-131/14:1/4
y=-131/14*4
y=-524/14
y=37 целых 6/14
2)6x+7/7=3-5x-3/8
6x+5x=3-3/8-1
11x=13/8
x=13/8:11
x=13/8*1/11
x=13/88
3)10-3x-1/2=6x+3/11
-3x-6x=1/2+3/11-10
-9x=-203
x=203/9
x=22 целых 7/9
4)4х-51/3-17-3х/4=х+5/2
4х-3х/4-х=17+17+5/2
(16х-3х-4х)/4=(34+34+5)/2
9х/4=73/2
18х=292
х=292:18
х=16 целых 4/18
х=16 целых 2/9