A Differential Equation is an equation with a function and one or more of its derivatives:
Example:
an equation with the function y and its derivative 
Homogeneous Differential Equations
A first order Differential Equation is Homogeneous when it can be in this form:
We can solve it using Separation of Variables but first we create a new variable 
With 
we can solve the Differential Equation.
Example
First, get it in 
form
Now, we have a function of (y/x).
Then, substitute
We’ll get
Now use Separation of Variables:
Put C in ln form with C = ln k
Now substitute back
We got the solution.