a)<BPC=2·32*15` =64*30` (2·15`=30`,2·32=64)
b)<BOC=48:3=16g>
<AOC=<AOB+<BOC=48+16=64*
c) <AOB=<AOC-<BOC=100-40*18`=99*60`-40*18`=59*42`
d)<BOC=x* <AOB=2x*=>
AOC=2x+x=3x =>
72*=3x x=72:3=24* <AOB=24* <AOC=2*24=48*
e) <BOC=x , <AOB=2x/3=>
<AOC=2x/3+x
75=5x/3 =>5x=225* x=225:5=45* => <BOC=45* =>,AOB=2/3·45=30*