32,4:18−1/2⋅[0,225:0,15−5⋅(2/5−0,81:0,9)]=
=324/10 : 18-1/2·[225/1000 : 15/100-5 (2/5-81/100 : 9/10)=
=162/5 · 1/18 -1/2·[15/10-5·(2/5-9/10)]=
=9/5 -1/2·[3/2-5·(2/5-9/10)]=
=9/5-1/2·[3/2-5·(4-9)/10]=
=9/5-1/2·[3/2+5/2]=
=9/5-1/2·8/2=
=9/5-2=(9-10)/5=-1/5=-0,2
