Your answer for -16 divided by 2 will be -8, because half of 16 is 8, but you are just in the negative numbers:)! So your answer is -8
If you notice, the container is really just two circles, with a diameter of 4 each, and a square with sides of 10.5.
now, if we just get the area of each circle, keeping in mind their radius is half of the diameter, namely r = 2, and get the area of the 10.5x10.5 square, sum them up, that'd be the surface area of the container.
Lcm is 24 and the gcf is 2
X= 36 I think
Hope this helps