The answer to your math problem is m= 5/2
There's nothing there, but the formula is LxWxH<span />
I think it could be 73. Because if you check what it the question says 73 fits them.
Since the area of the rectangle is 30, we know the following:
(5)(x-2) = 30
Divide both sides by 5
x-2 = 6
Add both sides by 2
x = 8
That's your answer.
Have an awesome day! :)