(c+d+r)+(-8,3) при c= - 9 4/5; d= - 10 9/20; r= -4,7
(c+d+r)+(-8,3) =c+d+r-8,3=-9 4/5-10 9/20-4.7-8,3= -9 4/5-10 9/20-13=-49/5-209/20-13= - 196/20-209/20-260/20=-665/20=-133/4=-33 1/4
спс