3又3/5*25又2/5+37.9*6又2/5=3.6*25.4+37.9*6.4
=(10-6.4)*25.4+37.9*6.4
=254+(37.9-25.4)*6.4
=254+12.5*6.4
=254+12.5*8*0.8
=254+100*0.8
=254+80
=334
3又3/5*25又2/5+37.9*6又2/5=3.6*25.4+37.9*6.4
=(10-6.4)*25.4+37.9*6.4
=254+(37.9-25.4)*6.4
=254+12.5*6.4
=254+12.5*8*0.8
=254+100*0.8
=254+80
=334