document.write( "Question 699687: solve x^2+6x+8=0 by graphing \n" ); document.write( "

Algebra.Com's Answer #431521 by mouk(232) $\"\"$ $\"About$

You can put this solution on YOUR website!
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Solved by pluggable solver: SOLVE quadratic equation with variable

Quadratic equation $\"ax%5E2%2Bbx%2Bc=0\"$ (in our case $\"1x%5E2%2B6x%2B8+=+0\"$ ) 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 $\"b%5E2-4ac\"$ : $\"b%5E2-4ac=%286%29%5E2-4%2A1%2A8=4\"$ .
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\n" ); document.write( " Discriminant d=4 is greater than zero. That means that there are two solutions: $\"+x%5B12%5D+=+%28-6%2B-sqrt%28+4+%29%29%2F2%5Ca\"$ .
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\n" ); document.write( " $\"x%5B1%5D+=+%28-%286%29%2Bsqrt%28+4+%29%29%2F2%5C1+=+-2\"$
\n" ); document.write( " $\"x%5B2%5D+=+%28-%286%29-sqrt%28+4+%29%29%2F2%5C1+=+-4\"$
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\n" ); document.write( " Quadratic expression $\"1x%5E2%2B6x%2B8\"$ can be factored:
\n" ); document.write( " $\"1x%5E2%2B6x%2B8+=+1%28x--2%29%2A%28x--4%29\"$
\n" ); document.write( " Again, the answer is: -2, -4.\n" ); document.write( "Here's your graph:
\n" ); document.write( " $\"graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+1%2Ax%5E2%2B6%2Ax%2B8+%29\"$

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