练习八1. (4÷3/5-5)÷2/3= (20/3-5)×3/2= 5/3×3/2= 5/2 (5/6+4/9)×18= 5/6×18+4/9×18= 15+8= 23 (2-1/3+2/3)×12= 2×12-1/3×12+2/3×12= 24-4+8= 282. 420×(1-1/6)=350(千克)3.(1)180×(1-1/5)=144(米)(2)180×1/5=36(米)4.(1)120×(1+9/10)=228(元) (2)120×(1-3/8)=75(元)5.(1)12/25×(1-1/8)=21/50(吨) (2)12/25-1/8=71/200(吨)6.(1)1/4×(1/8+1/3)=11/96(公顷) (2)1/4-11/96=13/96(公顷)7. 64+64×7/8=120(人) |