Ok so first you move them together so:
9x-3x=-36
6x=-36
x=
Then divide to get: -
6
Your answer would be
A
1 base. The triangular pyramid has 1 base, and that is the square at the bottom. Hope this helps.
IDK the constant and quantities...
First, find how many hours it takes for him to grade 1 essay, 0.16. Then multiply that by 35 to get 5.6.
I hope this is right -_-'