Giải các pt sau:

`e)` $\dfrac{x+1}{9}$`+`$\dfrac{x+2}{8}$`=`$\dfrac{x+3}{7}$`+`$\dfrac{x+4}{6}$ 

$\dfrac{x+1}{9}$`+``1+`$\dfrac{x+2}{8}$`+``1``=`$\dfrac{x+3}{7}$`+``1+`$\dfrac{x+4}{6}$`+1` 

$\dfrac{x+10}{9}$`+`$\dfrac{x+10}{8}$`=`$\dfrac{x+10}{7}$`+`$\dfrac{x+10}{6}$ 

$\dfrac{x+10}{9}$`+`$\dfrac{x+10}{8}$`-`$\dfrac{x+10}{7}$`-`$\dfrac{x+10}{6}$`=0` 

`(x+10)``(`$\dfrac{1}{9}$`+`$\dfrac{1}{8}$`-`$\dfrac{1}{7}$`-`$\dfrac{1}{6}$`)``=0` 

ĐK: $\dfrac{1}{9}$`+`$\dfrac{1}{8}$`-`$\dfrac{1}{7}$`-`$\dfrac{1}{6}$$\ne$`0`

`x+10=0`

`x=-10`

Vậy `x=-10`

`f)` $\dfrac{x-2}{98}$`+`$\dfrac{x-4}{96}$`=`$\dfrac{x-6}{94}$`+`$\dfrac{x-8}{92}$ 

$\dfrac{x-2}{98}$`-``1+`$\dfrac{x+4}{96}$`-``1``=`$\dfrac{x-6}{94}$`-``1+`$\dfrac{x-8}{92}$`-1` 

$\dfrac{x-100}{98}$`+`$\dfrac{x-100}{96}$`=`$\dfrac{x-100}{94}$`+`$\dfrac{x-100}{92}$ 

$\dfrac{x-100}{98}$`+`$\dfrac{x-100}{96}$`-`$\dfrac{x-100}{94}$`-`$\dfrac{x-100}{92}$`=0` 

`(x-100)``(`$\dfrac{1}{98}$`+`$\dfrac{1}{96}$`-`$\dfrac{1}{94}$`-`$\dfrac{1}{92}$`)``=0` 

ĐK: $\dfrac{1}{98}$`+`$\dfrac{1}{96}$`-`$\dfrac{1}{94}$`-`$\dfrac{1}{92}$$\ne$`0`

`x-100=0`

`x=100`

Vậy `x=100` 

$#chithanh17062010$