3/4-5/3 1/4-1/8=3/4+1/4-1又2/3-1/8=-2/3-1/8=--(16+3)/24=-19/24
3/4-5/3=9/12-20/12= - 11/12= - 0.916666666666671/4-1/8=2/8-1/8=1/8
3/4-5/3+1/4-1/8=(3/4+1/4)-1-2/3-1/8=-(2/3+1/8)=-19/24
