<span><span>A cargo plane flew to Moscow and back.
It took six hours longer to go there than it did to come back.
The average speed on the trip there was 152 mph.
The </span></span><span>average speed on the way back was 380 mph.
How many hours did the trip there take?
(x + 6)152 = 380x
228x = 912
x = 4
The trip there took 10 hours.</span>
Critical points is where the derivative (slope) is zero or does not exist. So to do this we have to find the derivative of our function:

So we apply chain rule:
=

Set our first derivative to zero and solve for x:
3(x^2 - 1) * 2x = 0
So we can see that (by plugging in) 0, -1 and 1 makes our solution true
So our critical value is x = 0, x = -1, x = 1
Cuboid C is 4 and 4. Cuboid D is 2 and 4.
The answer is x=2 i hope this helps !!
9/12 is the answer, you can't simply then down anymore