41.2*8.1+一又四分子一+53.7*1.9
=41.2*8.1+1.25+53.7*1.9
=41.2*8.1+1.25+(41.2+12.5)*1.9
=41.2*8.1+1.25+41.2*1.9+12.5*1.9
=(41.2*8.1+41.2*1.9)+(12.5*0.1+12.5*1.9)
=41.2*(8.1+1.9)+12.5*(0.1+1.9)
=41.2*10+12.5*2
=412+25
=437