41.2*8.1+11*9.25+537*0.19 =41.2*8.1+53.7*1.9+11*9.25 =41.2*(10-1.9)+53.7*1.9+11*9.25 =41.2*10-(41.2-53.7)*1.9+11*9.25 =412+12.5*1.9+11*9.25 =412+(1.1+0.8)*12.5+1.1*92.5 =412+10+(12.5+92.5)*1.1 =422+(100+5)*1.1 =422+110+5.5 =537.5