document.write( "Question 439757: $\"4k%28k%2B5%29=5\"$ \n" ); document.write( "

Algebra.Com's Answer #303929 by edjones(8007) $\"\"$ $\"About$

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4k(k+5)=5
\n" ); document.write( "4k^2+20k=5
\n" ); document.write( "4k^2+20k-5=0
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Solved by pluggable solver: SOLVE quadratic equation with variable

Quadratic equation $\"ax%5E2%2Bbx%2Bc=0\"$ (in our case $\"4x%5E2%2B20x%2B-5+=+0\"$ ) 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 $\"b%5E2-4ac\"$ : $\"b%5E2-4ac=%2820%29%5E2-4%2A4%2A-5=480\"$ .
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\n" ); document.write( " Discriminant d=480 is greater than zero. That means that there are two solutions: $\"+x%5B12%5D+=+%28-20%2B-sqrt%28+480+%29%29%2F2%5Ca\"$ .
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\n" ); document.write( " $\"x%5B1%5D+=+%28-%2820%29%2Bsqrt%28+480+%29%29%2F2%5C4+=+0.238612787525831\"$
\n" ); document.write( " $\"x%5B2%5D+=+%28-%2820%29-sqrt%28+480+%29%29%2F2%5C4+=+-5.23861278752583\"$
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\n" ); document.write( " Quadratic expression $\"4x%5E2%2B20x%2B-5\"$ can be factored:
\n" ); document.write( " $\"4x%5E2%2B20x%2B-5+=+4%28x-0.238612787525831%29%2A%28x--5.23861278752583%29\"$
\n" ); document.write( " Again, the answer is: 0.238612787525831, -5.23861278752583.\n" ); document.write( "Here's your graph:
\n" ); document.write( " $\"graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+4%2Ax%5E2%2B20%2Ax%2B-5+%29\"$

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