41.8×8.1+11×1.25+53.7×1.9 =41.8*（10-1.9）+53.7*1.9+11*1.25 =418-41.8*1.9+53.7*1.9+11*1.25 =418+1.9*（53.7-41.8）+11*1.25 =418+1.9*11.9+（10+1）*（1+1.25） =418+（2-0.1）*（11+0.9）+11+12.5+1+1.25 ...