41.2*8.1+11*1.25+53.7*1.9
=41.2*8.1+11*1.25+(41.2+12.5)*1.9
=41.2*8.1+41.2*1.9+11*1.25+12.5*1.9
=41.2*(8.1+1.9)+12.5*(11+1.9)