Question 121304
The demand equation for a certain type of printer is given by 
D = -200p + 35,000
the supply equation is predicted to be
S = -p^2 + 400p - 20,000
Find the equilibrium price. 
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Equilibrium occurs when supply equal demand.
EQUATION:
-200p+35000 = -p^2+400p-20000
p^2 - 600p +55000 = 0
p = [600 +- sqrt(600^2-4*55000)]/2
p = [600 +- sqrt140000]/2
Positive answer:
p = (600+374.1657)/2
p = $487.08
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Cheers,
Stan H.