document.write( "Question 164117This question is from textbook
\n" ); document.write( ": Solve algebraically and check your potential solutions: squareroot of x+20-x=0 \n" ); document.write( "

Algebra.Com's Answer #120923 by Earlsdon(6294) $\"\"$ $\"About$

You can put this solution on YOUR website!
Solve for x, check solutions:
\n" ); document.write( " $\"sqrt%28x%2B20%29-x+=+0\"$ Is this right? You really ought to use parentheses around the radicand to make it clear.\r
\n" ); document.write( "\n" ); document.write( " $\"sqrt%28x%2B20%29-x+=+0\"$ Add x to both sides.
\n" ); document.write( " $\"sqrt%28x%2B20%29+=+x\"$ Square both sides.
\n" ); document.write( " $\"x%2B20+=+x%5E2\"$ Rewrite this as:
\n" ); document.write( " $\"x%5E2-x-20+=+0\"$ Factor.
\n" ); document.write( " $\"%28x%2B4%29%28x-5%29+=+0\"$
\n" ); document.write( " $\"x%2B4+=+0\"$ or $\"x-5+=+0\"$ , so...
\n" ); document.write( " $\"x+=+-4\"$ or $\"x+=+5\"$
\n" ); document.write( "Check:
\n" ); document.write( " $\"sqrt%28x%2B20%29-x+=+0\"$ Substitute x = -4.
\n" ); document.write( " $\"sqrt%28-4%2B20%29-%28-4%29+=+sqrt%2816%29%2B4\"$ Evaluate.
\n" ); document.write( " $\"sqrt%2816%29%2B4++=+4%2B4\"$ = $\"8\"$ Nope! or $\"sqrt%2816%29%2B4+=+-4%2B4\"$ = $\"0\"$ OK!
\n" ); document.write( "--------------------
\n" ); document.write( " $\"sqrt%28x%2B20%29-x+=+0\"$ Substitute x = 5.
\n" ); document.write( " $\"sqrt%285%2B20%29-5+=+sqrt%2825%29-5\"$ Evaluate.
\n" ); document.write( " $\"sqrt%2825%29-5+=+5-5\"$ = $\"0\"$ OK! or $\"-5-5+=+-10\"$ Nope! \n" ); document.write( "

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