а)2 целые 1/6-(х+1 целая 112)=0,25
б) 8 целых 13-(5 целых 215-х)=3 целые 29

2 1/6 - (х-1 1/12) = 1/4
13/6 - (х-13/12) = 1/4
26/12 - (х-13/12)=3/12
26/12-х+13/12=3/12
26/12+13/12-3/12=х
36/12=х
х=4

8 1/3 - (5 2/15 -х)= 3 2/9
25/3 - (77/15 - х) = 29/9
375/45 - (231/45-х)=145/45
375/45-231/45+х=145/45
х=145/45-375/45+231/45
х=1/45