解答如下:(1/2-1/6)×5+1/4×4/5=1/3×5+1/5=5/3+1/5=28/15 11/28×8/33+13/14×25/26=2/21+25/28=83/844/7×5/8-2/21×3/4=5/14-1/14=2/71/2×1/3+1/15×(3/4-1/8)=1/6+1/15×5/8=1/6+1/24=5/247/12-3/24×5×12/15=7/12-1/2=1/126/7+3/4×5/6×2/7=6/7+5/28=29/28