Answer:
216*b^2
Explanation:
first, remember that:
a*√b = √(a^2*b)
√a*√b = √(a*b)


Now, our expression is:

Where in the right I rewrite the expression so it is easier to work.
Now we can use the second property of the above ones, to have:

And we know that:

Then:

and 12*12 = 144, then:
