Question 54959
 p = -x/2 + 75. I need to find the unit price when the following quantities are sold: 9 and 11. 
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P(9)=-9/2 + 75
=-4.5+75
=71.5
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p(11)=-11/2 + 75
=-5.5 + 75
=69.5
Cheers,
Stan H.