=(1.8-1.8)+(8.2+8.2)=0+16.4=16.4
(10,8+8.2)-(8.2-1.8)=16.4
1.8-1.8+8.2+8.2=16.4
1.8-1.8+8.2+8.2 =16.4
1.8-1.8+8.2+8.2=16.2