18又3/5*19/20+2又2/5*19/20-19/20

问题描述:

18又3/5*19/20+2又2/5*19/20-19/20

18又3/5*19/20+2又2/5*19/20-19/20
=93/5X19/20+12/5X19/20-19/20
=19/20X(93/5+12/5-1)
=19/20x100/5
=19/20-20
=19又1/20