What is the solution of the differential equation (x + y) (dx - dy) = dx + dy?
1
\(2\log \left( {x + y} \right) = c\left( {y - x} \right)\)
2
\(\left( {y - x} \right) + \log \left( {x + y} \right) = c\)
3
\(\left( {\frac{y}{x}} \right) + \left[ {\log \left( {\frac{y}{x}} \right)} \right] = c\)
4
None of the above