So sánh: `d) 7/3^2 + 7/3^3 + 7/3^4` và `8/3^2 + 8/3^3 + 8/3^4` 03/10/2021 Bởi Caroline So sánh: `d) 7/3^2 + 7/3^3 + 7/3^4` và `8/3^2 + 8/3^3 + 8/3^4`
`c)` Có: `7/3^2 <8/3^2` `7/3^3 <8/3^3` `7/3^3 <8/3^4` `=>7/3^2 +7/3^3 +7/3^4 <8/3^2 +8/3^3 +8/3^4` Bình luận
xl lần đầu gõ latex nên hơi chậm :v `7/3^2`+`7/3^3`+`7/3^4`=`91/81` `8/3^2`+`8/3^3`+`8/3^4`=`104/81` vì `91/81` < `104/81` nên `7/3^2`+`7/3^3`+`7/3^4` < `8/3^2`+`8/3^3`+`8/3^4` Bình luận
`c)`
Có:
`7/3^2 <8/3^2`
`7/3^3 <8/3^3`
`7/3^3 <8/3^4`
`=>7/3^2 +7/3^3 +7/3^4 <8/3^2 +8/3^3 +8/3^4`
xl lần đầu gõ latex nên hơi chậm :v
`7/3^2`+`7/3^3`+`7/3^4`=`91/81`
`8/3^2`+`8/3^3`+`8/3^4`=`104/81`
vì `91/81` < `104/81`
nên `7/3^2`+`7/3^3`+`7/3^4` < `8/3^2`+`8/3^3`+`8/3^4`