document.write( "Question 1001292: Which is the extraneous solution of -x = √2x+15?
\n" ); document.write( "The options are -5, -3, 3, or 5.\r
\n" ); document.write( "\n" ); document.write( "Extraneous solutions are very hard for me to find. Thank you for any help!
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Algebra.Com's Answer #618529 by KMST(5328)\"\" \"About 
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Solutions to \"-x=sqrt%282x%2B15%29\" will be some of the solutions to \"%28-x%29%5E2=%28sqrt%282x%2B15%29%29%5E2\" .
\n" ); document.write( "We solve the second equation:
\n" ); document.write( "\"x%5E2=2x%2B15\"
\n" ); document.write( "\"x%5E2-2x=15\"
\n" ); document.write( "\"x%5E2-2x%2B1=16\"
\n" ); document.write( "\"%28x-1%29%5E2=16\"
\n" ); document.write( "The solutions are:
\n" ); document.write( "\"x-1=4\"--->\"x=5\" , and
\n" ); document.write( "\"x-1=-4\"--->\"x=-3\" .
\n" ); document.write( "If one of them is not a solution of the original equation,
\n" ); document.write( "that one is an extraneous solution.
\n" ); document.write( "Since \"-x=sqrt%282x%2B15%29\" obviously requires a negative \"x\" ,
\n" ); document.write( "it is easy to see that 5 is an extraneous solution.
\n" ); document.write( "You can check and see that
\n" ); document.write( "\"x=-3\" is a solution to the original equation.
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