4,8+a-4,8-a+1,5=1,5
b-13,6-b+2,3/5=-13,6+2,6=-11
x-5/6-x-1/6=-6/6=-1
y+1/9-y+2,2/9-y+2/3=-у+2,3/9+2/3=-y+2,1/3+2/3=-y+3
