a) 8-3:4:(10:2-4)+ 20 =
b) (16-3-4)+(15-15:3) - (20:2-8) =
c) 4.2.5:10 + 112+5.3) -6.5 =
d! (3.4+4-5) - (12:3+20:4+2-5-6 =
e) 4.(9-3) +5.(12-7)=​