1. The problem statement, all variables and given/known data dy/dx = (x+3y)/(3x+y) I have to solve the given differential equation by using an appropriate substitution... 3. The attempt at a solution I used algebra to make the equation (3x+y)dy - (x+3y)dx = 0 then made x = vy and dx = vdy + ydv. then plugged in to get (3vy+y)dy - (vy+3y)(vdy+ydv) and now I'm looking for a common factor to cancel and I'm stuck, any help? Am I even headed in the right direction...thanks.