80.35×0.25＋4.197×2.5＋0.2903×25＋0.0865×25=

80.35×0.25＋4.197×2.5＋0.2903×25＋0.0865×25=
（0.8035+0.4197+0.2903+0.0865）*25=
1.6*25=40

此题用简便方法：
=80.35*0.25+[（4.197*10）*（2.5÷10）]+[（0.29.3*100)*(25÷100）]+[（0.0865*100)*(25÷100）]
=80.35*0.25+41.97*0.25+29.03*0.25+8.65*0.25
=(80.35+41.97+29.03+8.65)*0.25
=160*0.25
=40

80.35×0.25＋4.197×2.5＋0.2903×25＋0.0865×25
=(0.8035+0.4197+0.2903+0.0865)×25
=1.6×25
=0.4×(4×25)
=0.4×100
=40

80.35×0.25＋4.197×2.5＋0.2903×25＋0.0865×25
=(80.35+41.97+29.03+8.65)*0.25=40

80.35×0.25＋4.197×2.5＋0.2903×25＋0.0865×25
=25*(80.35/100+4.197/10+0.2903+0.0865)
=25*(0.8035+0.4197+0.2903+0.0865)
=25*1.6
=40

40
下次用计算机吖```