Begin with the fact that for all real a, and real b so long as .
So,
However, simplest form requires that you have no radicals in the denominator, so you have to perform a process called 'rationalizing the denominator.' To perform this process, you need to start with the ideas that for all real a and for all real a, . What we are going to do is multiply our expression by 1 in the form of .
And that is the simplest form for the given expression.