1、0.7×5/8+0.3×3/8=0.1x ( 35 /8 + 9/8 )= 0. 1x44/8= 0.1x5.5= 0.55 2、1/4-1/10÷2= 1/4 -1/20= ( 5-1) /20= 4 / 20=5分之13、5/6×（2÷5/8-3）=5/6 x( 2x 8/5 -3 )= 5/6 x(1...