document.write( "Question 451609: Use Tickests=-0.2x^2+12x+11 to determin the last day that tickets will be sold. \n" ); document.write( "
Algebra.Com's Answer #310528 by nerdybill(7384)\"\" \"About 
You can put this solution on YOUR website!
Tickets = -0.2x^2+12x+11
\n" ); document.write( "set Tickets to 0 and solve for x:
\n" ); document.write( "0 = -0.2x^2+12x+11
\n" ); document.write( "apply the \"quadratic formula\" to get:
\n" ); document.write( "x = {-0.9, 60.9}
\n" ); document.write( "throw out the negative solution leaving:
\n" ); document.write( "x = 60.9
\n" ); document.write( "solution: 61 days
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\n" ); document.write( "Details of quadratic follows:
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Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation \"ax%5E2%2Bbx%2Bc=0\" (in our case \"-0.2x%5E2%2B12x%2B11+=+0\") has the following solutons:
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\n" ); document.write( " \"x%5B12%5D+=+%28b%2B-sqrt%28+b%5E2-4ac+%29%29%2F2%5Ca\"
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\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=%2812%29%5E2-4%2A-0.2%2A11=152.8\".
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\n" ); document.write( " Discriminant d=152.8 is greater than zero. That means that there are two solutions: \"+x%5B12%5D+=+%28-12%2B-sqrt%28+152.8+%29%29%2F2%5Ca\".
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\n" ); document.write( " \"x%5B1%5D+=+%28-%2812%29%2Bsqrt%28+152.8+%29%29%2F2%5C-0.2+=+-0.903074280724887\"
\n" ); document.write( " \"x%5B2%5D+=+%28-%2812%29-sqrt%28+152.8+%29%29%2F2%5C-0.2+=+60.9030742807249\"
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\n" ); document.write( " Quadratic expression \"-0.2x%5E2%2B12x%2B11\" can be factored:
\n" ); document.write( " \"-0.2x%5E2%2B12x%2B11+=+-0.2%28x--0.903074280724887%29%2A%28x-60.9030742807249%29\"
\n" ); document.write( " Again, the answer is: -0.903074280724887, 60.9030742807249.\n" ); document.write( "Here's your graph:
\n" ); document.write( "\"graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+-0.2%2Ax%5E2%2B12%2Ax%2B11+%29\"

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