а) <span>5d=-85,6-3d</span>
8d+85.6=0
d=-85.6/8
d=-10.7
б) (5b)/6-(5b+1)/9=(1b)/2+1//3
(5//6)b-(5*b/9+1/9)-b/2-(1//3)=0
(5//6)b-((5//9)b+(1//9))-b/2-(1//3)=0
(5//18)b-(1//9)-b/2-(1//3)=0
-(2//9)b-(1//9)-(1//3)=0
-(2//9)b-(4//9)=0
b=(4//9)/(-(2//9))
b=-2
// - черта дроби
(7 4/19-2 8/19)+(8-4 12/19)=8 3/19
1) 7 4/19-2 8/19=6 23/19-2 8/19=4 15/19
2) 8-4 12/19=7 19/19-4 12/19=3 7/19
3) 4 15/19+3 7/19=7 22/19=8 3/19