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avatar+865 

In an equation of the form k = ax^2 + bx + c with a > 0, the least possible value of k occurs at x = -b/(2a). In the equation k = (6x + 12)(x - 8), what is the least possible value for k?

 May 29, 2020
 #1
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-1

From your formula, x = (-36)/(2) = -18, so the minimum value of k is (6(-18) + 12)((-18) - 8) = 2496.

 May 29, 2020
 #2
avatar+865 
0

how did you get those numbers

 May 29, 2020
 #3
avatar+23246 
+2

y  =  (6x + 12)(x - 8)   --->   y  =  6x2 - 48x + 12x - 96   --->   y  =  6x2 - 36x - 96

                a  =  6         b  =  - 36          c  =  - 96

 

Using the formula:  x  =  - b / (2a)   --->   x  =  - -36 / (2 · 6)     --->   x  =  36 / 12     --->   x  =  3

 

Place this back into the equation  y  =  (6x + 12)(x - 8)   --->   y  =  (6·3 + 12)(3 - 8)   --->   y  =  30 · -5

   --->   y  =  -150

 May 29, 2020
 #4
avatar+865 
0

PHEW. THANK YOU SO MUCH

AnimalMaster  May 29, 2020

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