document.write( "Question 42476: Please help with this word problem.\r
\n" ); document.write( "\n" ); document.write( "The demand equation for a certain type of printer is given by
\n" ); document.write( "D = -200p + 35000
\n" ); document.write( "The supply equation is predicted to be
\n" ); document.write( "S = -p^2 + 400p - 20000\r
\n" ); document.write( "\n" ); document.write( "Find the equilibrium price.\r
\n" ); document.write( "\n" ); document.write( "Thanks!!
\n" ); document.write( "

Algebra.Com's Answer #27594 by Nate(3500)\"\" \"About 
You can put this solution on YOUR website!
The demand equation for a certain type of printer is given by
\n" ); document.write( "D = -200p + 35000 or y = -200p + 35000
\n" ); document.write( "The supply equation is predicted to be
\n" ); document.write( "S = -p^2 + 400p - 20000 or y = -p^2 + 400p - 20000
\n" ); document.write( "So ....
\n" ); document.write( "y = -p^2 + 400p - 20000
\n" ); document.write( "-200p + 35000 = -p^2 + 400p - 20000
\n" ); document.write( "0 = -p^2 + 600p - 55000
\n" ); document.write( "\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "
Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation \"ap%5E2%2Bbp%2Bc=0\" (in our case \"-1p%5E2%2B600p%2B-55000+=+0\") has the following solutons:
\n" ); document.write( "
\n" ); document.write( " \"p%5B12%5D+=+%28b%2B-sqrt%28+b%5E2-4ac+%29%29%2F2%5Ca\"
\n" ); document.write( "
\n" ); document.write( " For these solutions to exist, the discriminant \"b%5E2-4ac\" should not be a negative number.
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\n" ); document.write( " First, we need to compute the discriminant \"b%5E2-4ac\": \"b%5E2-4ac=%28600%29%5E2-4%2A-1%2A-55000=140000\".
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\n" ); document.write( " Discriminant d=140000 is greater than zero. That means that there are two solutions: \"+x%5B12%5D+=+%28-600%2B-sqrt%28+140000+%29%29%2F2%5Ca\".
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\n" ); document.write( " \"p%5B1%5D+=+%28-%28600%29%2Bsqrt%28+140000+%29%29%2F2%5C-1+=+112.917130661303\"
\n" ); document.write( " \"p%5B2%5D+=+%28-%28600%29-sqrt%28+140000+%29%29%2F2%5C-1+=+487.082869338697\"
\n" ); document.write( "
\n" ); document.write( " Quadratic expression \"-1p%5E2%2B600p%2B-55000\" can be factored:
\n" ); document.write( " \"-1p%5E2%2B600p%2B-55000+=+-1%28p-112.917130661303%29%2A%28p-487.082869338697%29\"
\n" ); document.write( " Again, the answer is: 112.917130661303, 487.082869338697.\n" ); document.write( "Here's your graph:
\n" ); document.write( "\"graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+-1%2Ax%5E2%2B600%2Ax%2B-55000+%29\"

\n" ); document.write( "\n" ); document.write( "\"+graph%28+1000%2C+1000%2C+100%2C+500%2C+-10%2C+10%2C+-x%5E2+%2B+600x+-+55000%29+\"
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