(adsbygoogle = window.adsbygoogle || []).push({}); 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.

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Ordinary Differential Equation by substitution.

**Physics Forums | Science Articles, Homework Help, Discussion**