In order to simplify this, we need to apply our knowledge of factoring, and of dividing rational expressions.

First, in the expression on the left, the numerator and the denominator can both be factored:

In the expression on the right, the numerator can be factored.

Now, the rules of dividing fractions require that we invert the fraction on the right, and multiply:

Common factors in numerator and denominator can be removed:

So, our solution is ** -1**.