Xin hãy giúp mình với ạ!

`b, (x - 1)/(2015) + (x -3)/(2013) = (x - 5)/(2011) + (x - 7)/(2009)`

`=> (x - 1)/(2015) - 1 + (x -3)/(2013) - 1 = (x - 5)/(2011) - 1 + (x - 7)/(2009) - 1`

`=> (x - 1 - 2015)/(2015) + (x - 3 - 2013)/(2013) = (x - 5 - 2011)/(2011) + (x - 7 - 2009)/(2009)`

`=> (x -2016)/(2015) + (x -2016)/(2013) = (x - 2016)/(2011) + (x - 2016)/(2009)`

`=> (x -2016)/(2015) + (x -2016)/(2013) - (x - 2016)/(2011) - (x - 2016)/(2009) = 0`

`=> (x - 2016) (1/(2015) + 1/(2013) - 1/(2011) - 1/(2009)) = 0`

Mà `1/(2015) + 1/(2013) - 1/(2011) - 1/(2009) \ne 0`

`=> x - 2016 = 0`

`=> x= 2016`

Vậy `x= 2016`

`b, (x + 1)/(10) + (x +1 )/(11) + (x + 1)/(12) = (x + 1)/(13) + (x + 1)/(14)`

`=> (x + 1)/(10) + (x +1 )/(11) + (x + 1)/(12) - (x + 1)/(13) - (x + 1)/(14) = 0`

`=> (x + 1)(1/(10) + 1/(11) + 1/(12) - 1/(13) - 1/(14)) = 0`

Mà `1/(10) + 1/(11) + 1/(12) - 1/(13) - 1/(14) \ne 0`

`=> x + 1 = 0`

`=> x = -1`

Vậy `x =-1`

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