Đáp án+Giải thích các bước giải:
`\color{navy}{\text{Bạn tham khảo~}}`
`a)` `(5/2)^{3}.(4/5)^3`
`=(5/{2}.4/{5})^3`
`=(20/10)^3`
`=2^3`
`=8`
`b)` `(1/9)^{2}:(1/3)^3`
`=1/{81}:{1}/27`
`=1/{81}.27`
`=27/81=1/3`
`c)` `(9/5)^{5}:(27/-20)^5`
`=(9/{5}:{27}/-20)^5`
`=(9/{5}.{-20}/27)^5`
`=(-180/135)^5`
`=-1024/243`
`d)` `3^{3}.9^{-1}`
`=3^{3}.(3^2)^{-1}`
`=3^{3}.3^{-2}`
`=3^{3+(-2)}`
`=3^{3-2}`
`=3^1=3`
