3/4×5/7×4/3-1=(3/4*4/3)*5/7-1=5/7-1=-2/713/12+1/4×7/6-11/8=13/3*1/4+1/4*7/6-1/4*11/2=1/4*(13/3+7/6-11/2)=1/4*(26/6+7/6-33/6)=1/4*0=0
