решение (3/16-0.45)*0.8-0.21:0.2

3/16-45/100=3/16-9/20=15/80-36/80=-21/80
-21/80*0,8=-21/80*4/5=-21/100=-0,21
0,21:0,2=1,05
-0,21-1,05=-1,26