document.write( "Question 259972: My book says the answer is -5 and -3, where am I missing it?
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\n" ); document.write( "x=\"8%2B-+sqrt+%2864-60%29%2F%282%29\"
\n" ); document.write( "x=\"8%2B-+sqrt+%284%29%2F%282%29\"
\n" ); document.write( "x=\"%288%2B2%29%2F%282%29=+10%2F2+=+5\"
\n" ); document.write( "x=\"%288-2%29%2F%282%29=+6%2F2+=3\" \n" ); document.write( "
Algebra.Com's Answer #191425 by Edwin McCravy(20056)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "I think you aren't being careful with your signs and\r\n" );
document.write( "with putting parentheses around what you are substituting.\r\n" );
document.write( "If your book says the solutions are -5 and -3, then you \r\n" );
document.write( "have typed one or two signs wrong in the original problem, \r\n" );
document.write( "or else the book has a typographical error, and sometimes \r\n" );
document.write( "they do.\r\n" );
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document.write( "You gave the problem as\r\n" );
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document.write( "\"x%5E2-8x-15=0\"\r\n" );
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document.write( "but the solutions to that are not -5 and -3.\r\n" );
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document.write( "You would have to have had this problem instead\r\n" );
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document.write( "\"x%5E2%2B8x%2B15=0\"  [not \"x%5E2-8x%2B15=0\" as the other tutor said.]\r\n" );
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document.write( "In order to get solutions -5 and -3.\r\n" );
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document.write( "Then you would factor and get\r\n" );
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document.write( "\"%28x%2B5%29%28x%2B3%29=0\"\r\n" );
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document.write( "and then you'd set each of those = 0 and get\r\n" );
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document.write( "x+5=0      x+3=0\r\n" );
document.write( "  x=-5       x=-3\r\n" );
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document.write( "But let's suppose it was as you thought\r\n" );
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document.write( "You have this:\r\n" );
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document.write( "\"x%5E2-8x-15=0\"\r\n" );
document.write( "x=\"%28-%28-8%29%2B-+sqrt%28%28-8%29%5E2-4%2A1%2A%28-15%29%29%29%2F%282%2A1%29\"\r\n" );
document.write( "x=\"8%2B-+sqrt+%2864%2B60%29%2F%282%29\"\r\n" );
document.write( "x=\"8%2B-+sqrt+%28124%29%2F%282%29\"\r\n" );
document.write( "x=\"8%2B-+sqrt+%284%2A31%29%2F%282%29\"\r\n" );
document.write( "x=\"%288%2B-+2sqrt%2831%29%29%2F%282%29\"\r\n" );
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document.write( "Then you'd factor 2 out of the top:\r\n" );
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document.write( "x=\"%282%284%2B-+sqrt%2831%29%29%29%2F%282%29\"\r\n" );
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document.write( "and then cancel the 2's\r\n" );
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document.write( "x=\"%28cross%282%29%284%2B-+sqrt%2831%29%29%29%2F%28cross%282%29%29\"\r\n" );
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document.write( "\"x=4%2B-+sqrt%2831%29\"\r\n" );
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document.write( "Edwin

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