If $x{{dy} \over {dx}} = y\left( {\log y - \log x + 1} \right),$ then the solution of the equation is :
$y\log \left( {{x \over y}} \right) = cx$
$x\log \left( {{y \over x}} \right) = cy$
$\log \left( {{y \over x}} \right) = cx$
$\log \left( {{x \over y}} \right) = cy$
