document.write( "Question 734375: solve the equation: x - 2 sqrt of x = 8 \n" ); document.write( "

Algebra.Com's Answer #448909 by nerdybill(7384) $\"\"$ $\"About$

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solve the equation: x - 2 sqrt of x = 8
\n" ); document.write( ".
\n" ); document.write( " $\"x+-+2sqrt%28x%29+=+8+\"$
\n" ); document.write( "This is a \"quadratic\".
\n" ); document.write( "Let $\"y+=+sqrt%28x%29\"$
\n" ); document.write( "then we can rewrite the equation as:
\n" ); document.write( " $\"y%5E2+-+2y+=+8\"$
\n" ); document.write( " $\"y%5E2+-+2y+-+8+=+0\"$
\n" ); document.write( " $\"%28y%2B2%29%28y-4%29+=+0\"$
\n" ); document.write( "y = {-2,4}
\n" ); document.write( ".
\n" ); document.write( "but, we needed x so:
\n" ); document.write( " $\"-2+=+sqrt%28x%29\"$
\n" ); document.write( " $\"4+=+x\"$
\n" ); document.write( "and
\n" ); document.write( " $\"4+=+sqrt%28x%29\"$
\n" ); document.write( " $\"16+=+x\"$
\n" ); document.write( " \n" ); document.write( "

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