Question

$(x+y)(dx-dy)=dx+dy$
Solve the above equation.

Answer 1

Given the differential equation

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

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

Now integrating both sides we

have,

$x-y=log|x+y|+e$ [where 'e' is

integrating constant]