Giải thích các bước giải:
`0,05` ( $\frac{2x - 2}{2009}$ + $\frac{2x}{2010}$ + $\frac{2x}{2011}$ ) = `3,3` - ($\frac{x - 1}{2009}$ + $\frac{x}{2010}$ + $\frac{x + 1}{2011}$ )
`<=>``0,1`( $\frac{x - 1}{2009}$ + $\frac{x}{2010}$ + $\frac{x + 1}{2011}$ ) + ( $\frac{x - 1}{2009}$ + $\frac{x}{2010}$ + $\frac{x + 1}{2011}$ ) = `3,3`
`<=>``1,1`( $\frac{x - 1}{2009}$ + $\frac{x}{2010}$ + $\frac{x + 1}{2011}$ ) = `3,3`
`<=>` $\frac{x - 1}{2009}$ + $\frac{x}{2010}$ + $\frac{x + 1}{2011}$ = `3`
`<=>` $\frac{x - 1}{2009}$ + $\frac{x}{2010}$ + $\frac{x + 1}{2011}$ - `3` = `0`
`<=>` ( $\frac{x - 1}{2009}$ - `1`) + ( $\frac{x}{2010}$ + `1` ) + ( $\frac{x + 1}{2011}$ + `1` ) = `0`
`<=>` $\frac{x - 2010}{2009}$ + $\frac{x - 2010}{2010}$ + $\frac{x - 2010}{2011}$ = `0`
`<=>` `( x- 2010 )`( $\frac{1}{2009}$ + $\frac{1}{2010}$ + $\frac{1}{2011}$ ) = `0`
`<=>` ` x- 2010` = `0`
`<=>` `x = 2010`
` Vậy ` `S` = `{ 2010 }`