document.write( "Question 48139: how do u slove -b + square root b to the second power subtract 4ac over 2a to slove n to the second power subtract 8n-4=0? using the quadratic formula step by step?? \n" ); document.write( "
Algebra.Com's Answer #31844 by stanbon(75887)\"\" \"About 
You can put this solution on YOUR website!
n^2- 8n -4=0\r
\n" ); document.write( "\n" ); document.write( "n=[8+-sqrt(64-4(-4)/2\r
\n" ); document.write( "\n" ); document.write( "n=[8+-sqrt80]/2
\n" ); document.write( "n=[8+-4sqrt(5)]/2
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Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation \"an%5E2%2Bbn%2Bc=0\" (in our case \"1n%5E2%2B-8n%2B-4+=+0\") has the following solutons:
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\n" ); document.write( " \"n%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=%28-8%29%5E2-4%2A1%2A-4=80\".
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\n" ); document.write( " Discriminant d=80 is greater than zero. That means that there are two solutions: \"+x%5B12%5D+=+%28--8%2B-sqrt%28+80+%29%29%2F2%5Ca\".
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\n" ); document.write( " \"n%5B1%5D+=+%28-%28-8%29%2Bsqrt%28+80+%29%29%2F2%5C1+=+8.47213595499958\"
\n" ); document.write( " \"n%5B2%5D+=+%28-%28-8%29-sqrt%28+80+%29%29%2F2%5C1+=+-0.47213595499958\"
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\n" ); document.write( " Quadratic expression \"1n%5E2%2B-8n%2B-4\" can be factored:
\n" ); document.write( " \"1n%5E2%2B-8n%2B-4+=+1%28n-8.47213595499958%29%2A%28n--0.47213595499958%29\"
\n" ); document.write( " Again, the answer is: 8.47213595499958, -0.47213595499958.\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-8%2Ax%2B-4+%29\"

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\n" ); document.write( "\n" ); document.write( "Hope this helps.
\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.
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