# SOLUTION: 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. My answer is: D=S -200p+

Algebra ->  Algebra  -> Customizable Word Problem Solvers  -> Finance -> SOLUTION: 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. My answer is: D=S -200p+      Log On

 Ad: Over 600 Algebra Word Problems at edhelper.com Ad: Algebra Solved!™: algebra software solves algebra homework problems with step-by-step help! Ad: Algebrator™ solves your algebra problems and provides step-by-step explanations!

 Word Problems: Money, Business and Interest Solvers Lessons Answers archive Quiz In Depth

 Question 88618: 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. My answer is: D=S -200p+35000=p^2+400p-20000 p^2-600p+55000=0 Whereas p^2+ap+b=0, Am I right??? Thanks ;0)Answer by jim_thompson5910(28595)   (Show Source): You can put this solution on YOUR website!I'm assuming you're looking for the equilibrium price right? To find the equilibrium price, set D equal to S Subtract from both sides Subtract from both sides Add to both sides Combine like terms Now 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=-600, and c=55000 Negate -600 to get 600 Square -600 to get 360000 Multiply to get Combine like terms in the radicand (everything under the square root) Simplify the square root Multiply 2 and -1 to get -2 So now the expression breaks down into two parts or that simplify to or Which approximate to or So our possible solutions are: or Since a negative price doesn't make sense, we must discard the negative solution So the equilibrium price is \$80.79