С+д-8,3 при с= -9 4/5 д= - 1 9/20
-9 4/5+(- 1 9/20)-8,3=-49/5-29/20-8,3=-49*4/20-29/20-8,3=-196/20-29/20-8,3=-225/20-8,3=-225/20-83/10=-225/20-166/20=-391/20=-19 11/20