Đáp án: ` x= -2014`
Giải thích các bước giải:
` (x+4)/2010 + (x+3)/2011 = (x+2)/2012 + (x+1)/2013`
`<=> (x+4)/2010 + 1 + (x+3)/2011 +1 = (x+2)/2012 +1 + (x+1)/2013 +1`
`<=> (x+4+2010)/2010 + (x+3+2011)/2011 = (x+2+2012)/2012 + (x+1+2013)/2013`
`<=> (x+2014)/2010 + (x+2014)/2011 - (x+2014)/2012 - (x+2014)/2013 =0`
`<=> (x+2014) . (1/2010 + 1/2011 - 1/2012 - 1/2013) =0`
( Vì `1/2010 + 1/2011 - 1/2012 - 1/2013 \ne 0)`
`<=> x + 2014 =0`
`<=> x= -2014`