SOLUTION: this is a different one our instructor wrote for us. I have not a clue how to begin. at these prices it is estimated that the number of customers is related to the amount of ti

Algebra ->  Algebra  -> Customizable Word Problem Solvers  -> Misc -> SOLUTION: this is a different one our instructor wrote for us. I have not a clue how to begin. at these prices it is estimated that the number of customers is related to the amount of ti      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com
Ad: Algebrator™ solves your algebra problems and provides step-by-step explanations!
Ad: Algebra Solved!™: algebra software solves algebra homework problems with step-by-step help!

   

Question 44981: this is a different one our instructor wrote for us. I have not a clue how to begin.
at these prices it is estimated that the number of customers is related to the amount of time they must wait as,
N = -5t(squared)+80t-280, where t is time in minutes. When there are 35 customers what is the estimated wait time?
Answer by tutorcecilia(2144) About Me  (Show Source):
You can put this solution on YOUR website!
N = -5t(squared)+80t-280, where t is time in minutes. When there are 35 customers what is the estimated wait time?
N =35
35= -5t(squared)+80t-280
35 - 35 = -5t(squared)+80t-280-35 [Set the equation equal to zero]
0=-5t(squared)+80t-315 [solve using the quadratic formula]
x+=+%28-80+%2B-+sqrt%28+80%5E2-4%2A-5%2A-315+%29%29%2F%282%2A-5%29+
.
x+=+%28-80+%2B-+sqrt%28+6400-6300+%29%29%2F%28-10%29+
.
x+=+%28-80+%2B-+sqrt%28+100+%29%29%2F%28-10%29+
.-80+-10/-10
.-80+10/-10t = 7 minutes
.-80-10/-10 =9 minutes
Taking the average 9+7/2 = 8 minutes
.