14份之3+7份之4×99+15份之4
=3/14+(4/7)x99+4/15
=3/14+(8/14)x(100-1)+4/15
=3/14+800/14-8/14)+4/15
=(1/14)(3+800-8)+4/15
=795/14+4/15
=56+11/14+4/15
=56+(11/14+4/15)
=56+(165+56)/210
=56+221/210
=56+1+11/210
=57+11/210
=57又11/210
9.67－﹙2.67＋3.9﹚－6.1
=(9.67-2.67)-(3.9+6.1)
=7-10
=-3