document.write( "Question 931627: Solve equation Logarithm
\n" ); document.write( "\"log%285%2Cx%5E2%2Bx%2B4%29=2\" \n" ); document.write( "
Algebra.Com's Answer #565678 by ewatrrr(24785)\"\" \"About 
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\"log%285%2Cx%5E2%2Bx%2B4%29=2\"
\n" ); document.write( "x^2+x+4 = 5^2
\n" ); document.write( "x^2 + x - 21 = 0
\n" ); document.write( "x =
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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%2B1x%2B-21+=+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=%281%29%5E2-4%2A1%2A-21=85\".
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\n" ); document.write( " Discriminant d=85 is greater than zero. That means that there are two solutions: \"+x%5B12%5D+=+%28-1%2B-sqrt%28+85+%29%29%2F2%5Ca\".
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\n" ); document.write( " \"x%5B1%5D+=+%28-%281%29%2Bsqrt%28+85+%29%29%2F2%5C1+=+4.10977222864644\"
\n" ); document.write( " \"x%5B2%5D+=+%28-%281%29-sqrt%28+85+%29%29%2F2%5C1+=+-5.10977222864644\"
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\n" ); document.write( " Quadratic expression \"1x%5E2%2B1x%2B-21\" can be factored:
\n" ); document.write( " \"1x%5E2%2B1x%2B-21+=+1%28x-4.10977222864644%29%2A%28x--5.10977222864644%29\"
\n" ); document.write( " Again, the answer is: 4.10977222864644, -5.10977222864644.\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%2B1%2Ax%2B-21+%29\"
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