-8,7-2,3+5,9-4,9= (6,5-7,4)+(1,3-6,5-9,1)= -(67,45-6,58+2,98)-67,45=
=-11+1=10 =-0,9+(-14,3)=-15,2 =-(60,87+2,98)-67,45=-63,8-67,45=3,65