document.write( "Question 522808: Solve y2 = 15y − 56 using the quadratic formula
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Algebra.Com's Answer #347008 by Maths68(1474) $\"\"$ $\"About$

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y^2=15y-56
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Solved by pluggable solver: SOLVE quadratic equation with variable

Quadratic equation $\"ay%5E2%2Bby%2Bc=0\"$ (in our case $\"1y%5E2%2B-15y%2B56+=+0\"$ ) has the following solutons:
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\n" ); document.write( " $\"y%5B12%5D+=+%28b%2B-sqrt%28+b%5E2-4ac+%29%29%2F2%5Ca\"$
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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 $\"b%5E2-4ac\"$ : $\"b%5E2-4ac=%28-15%29%5E2-4%2A1%2A56=1\"$ .
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\n" ); document.write( " Discriminant d=1 is greater than zero. That means that there are two solutions: $\"+x%5B12%5D+=+%28--15%2B-sqrt%28+1+%29%29%2F2%5Ca\"$ .
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\n" ); document.write( " $\"y%5B1%5D+=+%28-%28-15%29%2Bsqrt%28+1+%29%29%2F2%5C1+=+8\"$
\n" ); document.write( " $\"y%5B2%5D+=+%28-%28-15%29-sqrt%28+1+%29%29%2F2%5C1+=+7\"$
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\n" ); document.write( " Quadratic expression $\"1y%5E2%2B-15y%2B56\"$ can be factored:
\n" ); document.write( " $\"1y%5E2%2B-15y%2B56+=+1%28y-8%29%2A%28y-7%29\"$
\n" ); document.write( " Again, the answer is: 8, 7.\n" ); document.write( "Here's your graph:
\n" ); document.write( " $\"graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+1%2Ax%5E2%2B-15%2Ax%2B56+%29\"$

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