Question

Solve :

$(x+y)(dx-dy)=dx+dy$.

Answer 1

Given the differential equation,

$(x+y)(dx-dy)=dx+dy$

or, $\frac{dy+dx}{x+y}=dx-dy$

Now integrating both sides we get,

or, $\log |(x+y)|=x-y+c$ [ Where $c$ is integrating constant]