Answer:

The only limitation is for r which must not be zero
Explanation:
Solving Equations
We need to perform some steps to isolate the required variable and solve the equation. It's commonly the application of algebraic operations contrary to the ones already present in the expression to work with
We have

And we need to solve for y
Let's add -s to both sides of the equation

Simplifying

Now we divide by r

Solving

The only limitation is for r which must not be zero