SOLUTION: The number N of guests that arrive at a mall food court each hour can be approximated by N = -12x2 + 110x + 35, where x is the number of hours after 11:00 a.m. At what times, to th

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Question 88548: The number N of guests that arrive at a mall food court each hour can be approximated by N = -12x2 + 110x + 35, where x is the number of hours after 11:00 a.m. At what times, to the nearest minute, are 200 guests per hour arriving at the food court?


Answer by checkley75(3666) About Me  (Show Source):
You can put this solution on YOUR website!
200=-12x^2+110x+35
-12x^2+110x+35-200=0
12x^2-110x+165=0
using the quadratic equation x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+ we get:
x=(110+-sqrt[110^2-4*12*165])/2*12
x=(110+-sqrt[12100-7920])/24
x=(110+-sqrt4180)/24
x=(110+-64.65)/24
x=(110+64.65)/24
x=174.65/24
x=7.28 hours or 7 hours & 17 minutes after 11:00 am. is one answer.
x=(110-64.65)/24
x=45.35/24
x=1.9 or 1 hour & 54 minutes after 11:00 am is the other answer.