It's

because this choice made the most since.
To find the volume of each prism, you will multiply the length by the width by the height.
V = lwh
3 3/4 x 3 x 3 1/4
V = 36 9/16 cubic feet
V = lwh
1/4 x 1/4 x 1/4
V= 1/64 cubic feet
Both boxes are similar in that they can be described as a rectangular prism.
They are different because one prism has congruent edges, so we call it a cube. The other one has varying side lengths, therefore it is only a rectangular prism.
I’m hoping you are talking about:
Factor -1/2 out of -1/2x + 6
If so then the answer is
-1/2(x-3)