<PRE><B>Question 1051963</B>
Let h be the number of hours, then
:
1) (25-2h) * (12+3h) = total amount made in h hours (T)
:
-6h^2 +51h +300 = T
:
The graph of this function is a parabola that curves downward, we want the 
coordinates of the vertex of the parabola
:
x value = -b / 2a = -51 / (2*(-6)) = 4.25
:
substitute x value for h in equation 1)
:
-6(4.25)^2 +51(4.25) + 300 = 408.375  approx 408.38
:
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25 - 2(4.25) = 16.50
:
She receives the most money at $16.50 / glass
:
She receives $408.38
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:
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