(x-1,15/16)+7,3/16=8,1/16+4,9/16
Какой икс?

(х-1 15/16)+7 3/16=8 1/16+4 9/16 
(х-1 15/16)+7 3/16=12 10/16
х-1 15/16=12 10/16-7 3/16
х-1 15/16=5 7/16
x=5 7/16+1 15/16
x=7 3/8

15 3/28-(4 11/28+у)=7-1 9/28
15 3/28-(4 11/28+у)=5 19/28
-(4 11/28+у)=15 3/28-5 19/28
4 11/28-y=9 12/28
y=9 12/28-4 11/28
y=5 1/28