а)(1-3/4)×(4/5-3/4)=1/4×1/20=1/80
б)14×(1/2+1/3+1/4)=14×13/12=182/12=15.1/6
в)1/3×6/7-1/7×3/4=2/7-3/28=5/28
а)(1-3/4)×(4/5-3/4)=1/4×1/20=1/80
б)14×(1/2+1/3+1/4)=14×13/12=182/12=15.1/6
в)1/3×6/7-1/7×3/4=2/7-3/28=5/28