document.write( "Question 245988: why dose $\"sqrt%284x%5E4%2B36x%2B81%29\"$ \r
\n" ); document.write( "\n" ); document.write( "= $\"2x%5E2%2B9\"$
\n" ); document.write( "and not
\n" ); document.write( "= $\"2x%5E2%2B6x%2B9\"$ \r
\n" ); document.write( "\n" ); document.write( "what happens to the 6??
\n" ); document.write( " \n" ); document.write( "

Algebra.Com's Answer #179673 by oberobic(2304) $\"\"$ $\"About$

You can put this solution on YOUR website!
When you factor $\"4x%5E4+%2B+36x%5E2+%2B+81\"$ you find that it =
\n" ); document.write( " $\"%282x%5E2+%2B+9%29%282x%5E2%2B9%29\"$
\n" ); document.write( ".
\n" ); document.write( "To check, multiply through:
\n" ); document.write( " $\"2x%5E2%2A2x%5E2+%2B+2x%5E2%2A9+%2B+9%2A2x%5E2+%2B+9%2A9\"$ =
\n" ); document.write( " $\"4x%5E4+%2B+18x%5E2+%2B+18x%5E2+%2B+81\"$
\n" ); document.write( " $\"4x%5E4+%2B+36x%5E2+%2B+81\"$ .
\n" ); document.write( "We observe that:
\n" ); document.write( " $\"%282x%5E2+%2B+9%29%282x%5E2%2B9%29\"$ is equivalent to:
\n" ); document.write( " $\"%282x%5E2+%2B+9%29%5E2\"$
\n" ); document.write( ".
\n" ); document.write( "So, $\"sqrt%282x%5E2+%2B+9%29%5E2%29\"$ equals:
\n" ); document.write( " $\"2x%5E2+%2B+9\"$
\n" ); document.write( ".
\n" ); document.write( "Note: I had to assume the original equation is as I wrote it, which has a $\"36x%5E2\"$ in the middle, not $\"36x\"$ . \n" ); document.write( "

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