41.2*8.1＋11*1.25＋53.7*1.9 如何简便计算？（脱式）

Question

*是乘号

Answer 1

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＋11*1.25＋41.2*1.9+12.5*1.9
=41.2*(8.1+1.9)+1.25(11+19)
=41.2*10+1.25*30
=412+37.5
=449.5