document.write( "Question 474168: Hi, i've literally tried everything to find out about the quadratic formula; can you help me solve this?
\n" ); document.write( "\"4k%5E2-81=0\"
\n" ); document.write( "directions say \"solve equation with the quadratic formula\"
\n" ); document.write( "thanks! (:
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Algebra.Com's Answer #325190 by Alan3354(69443)\"\" \"About 
You can put this solution on YOUR website!
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Solved by pluggable solver: SOLVE quadratic equation (work shown, graph etc)
Quadratic equation \"ax%5E2%2Bbx%2Bc=0\" (in our case \"4x%5E2%2B0x%2B-81+=+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=%280%29%5E2-4%2A4%2A-81=1296\".
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\n" ); document.write( " Discriminant d=1296 is greater than zero. That means that there are two solutions: \"+x%5B12%5D+=+%28-0%2B-sqrt%28+1296+%29%29%2F2%5Ca\".
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\n" ); document.write( " \"x%5B1%5D+=+%28-%280%29%2Bsqrt%28+1296+%29%29%2F2%5C4+=+4.5\"
\n" ); document.write( " \"x%5B2%5D+=+%28-%280%29-sqrt%28+1296+%29%29%2F2%5C4+=+-4.5\"
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\n" ); document.write( " Quadratic expression \"4x%5E2%2B0x%2B-81\" can be factored:
\n" ); document.write( " \"4x%5E2%2B0x%2B-81+=+%28x-4.5%29%2A%28x--4.5%29\"
\n" ); document.write( " Again, the answer is: 4.5, -4.5.\n" ); document.write( "Here's your graph:
\n" ); document.write( "\"graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+4%2Ax%5E2%2B0%2Ax%2B-81+%29\"

\n" ); document.write( "\n" ); document.write( "k = x\r
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