The coefficient of the second term is 18.
What you do is you FOIL the terms:
To find how much is in the pull in 11 hours, we can plug 11 in for t
W = 9000 -250(11)
W = 9000 - 2750
W = 6250 gallons
To find how long it will take to empty the pool, we can set the gallons equal to 0
0 = 9000 - 250t
To solve for t, we will first subtract both sides by 9000
-9000 = -250t
We will then divide both sides by -250
t = 36 hours
It is not possible. Since one of the angles has to be a right angle, the other two angles would have to add to 90. Therefore, neither of these angles can be more than 90 degrees.
Hope this helps
Dividing a said number by itself should get rid of its square