The given differential equation is:

dy/dx = 3y

This is a separable differential equation, meaning we can separate the variables y and x on opposite sides of the equation.

Step 1: Separate the variables

By rearranging the equations we get

dy/y = 3 dx

Step 2: Integrate both sides

Now, integrate both sides of the equation:

∫ (1/y) dy = ∫ 3 dx

ln|y| = 3x + C

Where C is the constant of integration.