Please explain #13, test 1, Section 3.

Yeah, this is a great question, right? 🙂

You’re given this:

You’re going to have to deal with it in two parts. First, get the bottom simplified. Step 1 is to multiply by some clever forms of 1 to get a common denominator:

Now multiply those fractions on the bottom. Your common denominator will be .

Now that you’ve got a common denominator, add to get one big fraction on the bottom.

From there, all you need to remember is that when you divide by a fraction, you flip the divisor and multiply. In other words:

So there you have it—the answer is **B**.