All,

I don know how to solve this linear ordinary DE given the transfomation v=x+y. I havent come across this before. I have solved other ones involving y=vx where v is a function of x, thereby usnig the product rule to get dy/dx etc

$\displaystyle

\frac{\text{dy}}{\text{dx}}=-\frac{x+y}{3 x+3 y-4}=-\frac{v}{3 v-4}

$

Any clues will be appreciated.

Thanks