\(pt\Leftrightarrow\left(\dfrac{x+5}{2005}+1\right)+\left(\dfrac{x+6}{2004}+1\right)+\left(\dfrac{x+7}{2003}+1\right)=0\)
\(\Leftrightarrow\dfrac{x+2010}{2005}+\dfrac{x+2010}{2004}+\dfrac{x+2010}{2003}=0\)
\(\Leftrightarrow\left(x+2010\right)\left(\dfrac{1}{2005}+\dfrac{1}{2004}+\dfrac{1}{2003}\right)=0\)
Mà \(\dfrac{1}{2005}+\dfrac{1}{2004}+\dfrac{1}{2003}\ne0\Rightarrow x+2010=0\Rightarrow x=-2010\)
Vậy \(x=-2010\)