1) Tính:
`a)``7/11``×``6/5``=``42/55`
`3``1/3``×5``1/4``=``10/3``×``21/4``=``35/2`
`b)``6/7``:``5/2``=``6/7``×``2/5``=``12/35`
`2``1/3``:1``1/4``=``7/3``:``5/4``=``7/3``×``4/5``=``28/15`
`c)``3/5``×``4/7``×1``1/2``=``3/5``×``4/7``×``3/2``=``18/35`
2)Tìm x:
`a)x×``2/5``=``4/7`
`x=``4/7``:``2/5`
`x=``10/7`
`b)x:``6/11``=``44/9`
`x=``44/9``×``6/11`
`x=``8/3`
`3,`
`a)8m78cm=8m+``78/100``cm=8``78/100``m`
`b)5m5cm=5m+``5/10``cm=5``5/10``m`
`c)3m9cm=3m+``9/10``cm=3``9/10``m`
4)khoanh tròn trước câu trả lời đúng:
`a)C,``14/3`
Vì: `4``2/3``=``(4×3+2)/3``=``14/3`
`b)B,12m`
Vì: `18×``2/3``=12m`
