document.write( "Question 642216: x^2-8x-4=0 ??
\n" ); document.write( "solve each equation by completing the square, thank you for the help I really need it. \n" ); document.write( "

Algebra.Com's Answer #403991 by nerdybill(7384) $\"\"$ $\"About$

You can put this solution on YOUR website!
$\"x%5E2-8x-4=0\"$
\n" ); document.write( " $\"x%5E2-8x+=+4\"$
\n" ); document.write( "take half 'b', square it, and add to both sides:
\n" ); document.write( " $\"x%5E2-8x%2B16+=+4%2B16\"$
\n" ); document.write( " $\"%28x-4%29%28x-4%29+=+20\"$
\n" ); document.write( " $\"%28x-4%29%5E2+=+20\"$
\n" ); document.write( "take the square root of both sides:
\n" ); document.write( " $\"%28x-4%29+=+sqrt%2820%29\"$
\n" ); document.write( " $\"x-4+=+sqrt%282%2A2%2A5%29\"$
\n" ); document.write( " $\"x-4+=+2%2Asqrt%285%29\"$
\n" ); document.write( " $\"x+=+2%2Asqrt%285%29%2B4\"$
\n" ); document.write( "so x can be two possibilities:
\n" ); document.write( " $\"x+=+2%2Asqrt%285%29%2B4\"$
\n" ); document.write( "and
\n" ); document.write( " $\"x+=+-2%2Asqrt%285%29%2B4\"$
\n" ); document.write( ".
\n" ); document.write( "or approximately,
\n" ); document.write( "x = {-0.47, 8.47}
\n" ); document.write( " \n" ); document.write( "

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