1.68/1.6=1.05
1.05-2.1=-1.05
-1.05*(-3/5)=0.63
0.63-13/6=63/100-13/6=378-1300/600=922/600=461/300
(168:1.6-2.1)*(-0.5)=-1.05*(-0.5)=21
1.68/1.6=1.05
1.05-2.1=-1.05
-1.05*(-3/5)=0.63
0.63-13/6=63/100-13/6=378-1300/600=922/600=461/300
(168:1.6-2.1)*(-0.5)=-1.05*(-0.5)=21