Help with a mathematics question - rationalising

I'm supposed to rationalise this question as follows, but I'm unsure of how to do it
Could anyone help me with the method?

12√a
--------------------------
(√a + 2)² - (√a - 2)²

I got the answer 12√a but I'm pretty sure it's not correct

Thanks in advance

Use the difference of two squares on the denominator.
Upload your working if problems.

Thing is they're squared so I'm unsure of how to use the difference of two squares

I got the answer 12√a but I'm pretty sure it's not correct

I'm supposed to rationalise this question as follows, but I'm unsure of how to do it
Could anyone help me with the method?

12√a
--------------------------
(√a + 2)² - (√a - 2)²

I got the answer 12√a but I'm pretty sure it's not correct

Thanks in advance

I've successfully figured out how to do the expansion brackets

12√a
----------
(a+4√a+4)-(a-4√a+4)

= 12√a
----------
8√a

But I can't for the life of me figure out how to find the difference between squares which I need to do

You don't to solve this question. What you have done, so far, is correct.

The difference of squares is:

$a^2-b^2=(a-b)(a+b)$

Applying that here is just a short-cut (although not that much of one):

$(\sqrt{a}+2)^2-(\sqrt{a}-2)^2=(\sqrt{a}+2-(\sqrt{a}-2))(\sqrt{a}+2+\sqrt{a}-2)=4(2\sqrt{a})=8\sqrt{a}$