2/3一5/6×3/10+3/2=2/3-1/4+3/2=（8-3+18）/12=23/12 7/4÷(2/3+1/2)x4/5=(7/4*4/5)/(7/6)=7/5*6/7=1.2 8/15÷9+1/9x7/15=1/15*(8/9+7/9)=1/15*15/9=1/9 [4一(3/4一3/8)]×4/29=[4-3/8]*4/29=29/8*4/29=1/2
