I don't know what posts are but i'm assuming you would subtract 21 from 17 and get 4.
The constraint on time is
.. 75W +15M ≥ 300 . . . . . . . minutes
The constraint on paper is
.. 3W +M ≤ 20 . . . . . . . . . . . sheets of paper
Answer:

Step-by-step explanation:

1. Multiply the length, width, and height to get the volume of the box, which is 24 ft³. 2. Each cube has a volume of 4, right? So divide 24 by 4 to get 6. 6 boxes can fit into the crate.
3y=6+x
y=(6+x)/3
y=2+x/3
y=mx+b
y=x/3+b
so m(slope) is 1/3
use the point (3, 5), sub this for x and y
5=3/3+b
5-1=b
b=4
therefore, y=x/3+4
or y=(1/3)x+4 (you can write it like this as well)