SOLUTION: The demand and supply equations for a certain item are given by: D=-5p+10 S=-p^2+30p-8 Find both possible solutions and determine the equilibrium price This is what I have

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Question 98233: The demand and supply equations for a certain item are given by:
D=-5p+10
S=-p^2+30p-8
Find both possible solutions and determine the equilibrium price

This is what I have so far:
-5p+40=-p^2+30p-8
p^2-35p+48=0
p^2-36p=-48 I am now unsure of what to do from here.
Thank you for your help

Answer by jim_thompson5910(35256)   (Show Source): You can put this solution on YOUR website!
To find the equilibrium, set the equations equal to one another




Get all terms to one side and combine like terms


Let's use the quadratic formula to solve for p:


Starting with the general quadratic



the general solution using the quadratic equation is:



So lets solve ( notice , , and )

Plug in a=1, b=-35, and c=48



Negate -35 to get 35



Square -35 to get 1225 (note: remember when you square -35, you must square the negative as well. This is because .)



Multiply to get



Combine like terms in the radicand (everything under the square root)



Simplify the square root (note: If you need help with simplifying the square root, check out this solver)



Multiply 2 and 1 to get 2

So now the expression breaks down into two parts

or


Now break up the fraction


or


Simplify


or


So these expressions approximate to

or


So our possible solutions are:
or



However, since generates a negative supply and demand, the only solution is

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