练习七1. 3/2 2/7 20 1/2 3/8 1/6 15/2 02.(1)10×4/5×5/8=5(吨) (2)36×2/3×3/4=18(个)3.(75+65)×6/7=120(千米)4. 6/5-3×1/4=9/20(升)5.(2/3+4/5)×3/4=11/10(吨)6. 2/3x+1/6x=1/4x-7/9x=2/153/5x+20=505/6x=1/42/9x=2/153/5x=30x=3/10 x=3/5 x=507. 7/13×2/5-2/13×2/5=(7/13-2/13)×2/5=5/13×2/5= 2/1324-24×18/19=24×(1-18/19)=24×1/19=24/195/7÷1/4+5/7÷3/4=5/7×4+7/5×4/ |