\(x\cdot2013-x=2013\cdot2011+2013\)
\(x\cdot\left(2013-1\right)=2013\cdot\left(2011+1\right)\)
\(x\cdot2012=2013\cdot2012\)
\(x=2013\cdot2012\div2012\)
\(x=2013\)
\(x\times2013-x=2013\times2011+2013\)
\(x\times\left(2013-1\right)=2013\times\left(2011+1\right)\)
\(x\times2012=2013\times2012\)
\(\Rightarrow x=2013\)
X × 2013 - X = 2013 × 2011 + 2013
(=) X ( 2013-1 ) = 2013× ( 2011 + 1 )
(=) X × 2012 = 2013 × 2012
(=) X = 2013
Vậy X = 2013