Answer:
Yes, it is a linear expression because the highest power of x is 1.
The volume of a cube = length x width x height. Since they told us this box has a square base, the length and width are both 18 inches.
V = 18 x 18 x 16
V = 5184 cubic inches or in^3
The second answer i believe
I think she can add 5p more of orange which is 9p and 6p more water which is 8p. I'm pretty sure this works because 9 is the next closest multiple of 3 and 8 is one number less than that. Hope this helps!