41.2×8.1+11×1.25+53.7×1.9
=41.2*(8+0.1)+12.5+1.25+53.7*(2-0.1)
=329.6+4.12+12.5+1.25+107.4-5.37
=449.5+4.12+1.25-5.37
=449.5+0
=449.5