We have:

We want to substitute in

But two things hinder us:

-The uneven powers of R

-The unequal constants.

Some quick division tells us that

So we have:

There are two ways to view the next step:

You could conceptualize it as multiplying through by to give:

And then you can make the substitution.

Or consider the fact that

We need in the numerator.

We currently have in the numerator. You can then deduce that so we can rewrite as

Either way, we are left with:

And we want to substitute in:

Which we can now do, leaving: