This is the start to the approach that would be taken to get both variables in terms of only one so it can be solved but since the numbers are so small you could easily test out numbers and figure out that it's 6 and 10 feet.
length = width + 4
length * width = 60
(width + 4) * width = 60
I have no idea I am sorry
The Answer is 1600
Hope this helps :)
So the larger number is x, and the smaller number is y
7y=x
3x=7+4y
(So plug in the 7y=x information into the second equation)
3(7y)=7+4y
21y=7+4y
17y=7
y=7/17
Over 5 weeks 20 reduction in waste removed.
Therefore 4 per week.
Therefore gradient -4w.
-4 x 5 + c = 60
-20 + c = 60
c = 80
dumpsters removed = d
weeks = w
d = 80 - 4w
