What is the solution of the differential equation \(\frac{{dx}}{{dy}} = \frac{{x\; + {\rm{\;}}y\; + {\rm{\;}}1}}{{x\; + {\rm{\;}}y\; - {\rm{\;}}1}}?\)
Where c is the arbitrary constant
1
y – x + 4ln(x + y) = c
2
y + x + 2 ln(x + y) = c
3
y – x + ln(x + y) = c
4
y + x - 2 ln (x + y) = c