document.write( "Question 167316: sqrtof 9x+81=x+5\r
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Algebra.Com's Answer #123255 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
\"sqrt%289x%2B81%29=x%2B5\" Start with the given equation\r
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\n" ); document.write( "\n" ); document.write( "\"9x%2B81=%28x%2B5%29%5E2\" Square both sides to get rid of the square root.\r
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\n" ); document.write( "\n" ); document.write( "\"9x%2B81=x%5E2%2B10x%2B25\" FOIL\r
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\n" ); document.write( "\n" ); document.write( "\"0=x%5E2%2B10x%2B25-9x-81\" Subtract 9x from both sides. Subtract 81 from both sides.\r
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\n" ); document.write( "\n" ); document.write( "\"0=x%5E2%2Bx-56\" Combine like terms.\r
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\n" ); document.write( "\n" ); document.write( "Notice we have a quadratic equation in the form of \"ax%5E2%2Bbx%2Bc\" where \"a=1\", \"b=1\", and \"c=-56\"\r
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\n" ); document.write( "\n" ); document.write( "Let's use the quadratic formula to solve for x\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-b+%2B-+sqrt%28+b%5E2-4ac+%29%29%2F%282a%29\" Start with the quadratic formula\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-%281%29+%2B-+sqrt%28+%281%29%5E2-4%281%29%28-56%29+%29%29%2F%282%281%29%29\" Plug in \"a=1\", \"b=1\", and \"c=-56\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-1+%2B-+sqrt%28+1-4%281%29%28-56%29+%29%29%2F%282%281%29%29\" Square \"1\" to get \"1\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-1+%2B-+sqrt%28+1--224+%29%29%2F%282%281%29%29\" Multiply \"4%281%29%28-56%29\" to get \"-224\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-1+%2B-+sqrt%28+1%2B224+%29%29%2F%282%281%29%29\" Rewrite \"sqrt%281--224%29\" as \"sqrt%281%2B224%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-1+%2B-+sqrt%28+225+%29%29%2F%282%281%29%29\" Add \"1\" to \"224\" to get \"225\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-1+%2B-+sqrt%28+225+%29%29%2F%282%29\" Multiply \"2\" and \"1\" to get \"2\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-1+%2B-+15%29%2F%282%29\" Take the square root of \"225\" to get \"15\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-1+%2B+15%29%2F%282%29\" or \"x+=+%28-1+-+15%29%2F%282%29\" Break up the expression. \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%2814%29%2F%282%29\" or \"x+=++%28-16%29%2F%282%29\" Combine like terms. \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+7\" or \"x+=+-8\" Simplify. \r
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\n" ); document.write( "\n" ); document.write( "So the possible answers are \"x+=+7\" or \"x+=+-8\"\r
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\n" ); document.write( "\n" ); document.write( "However, if you plug in \"x+=+-8\", then the equation won't be true.\r
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\n" ); document.write( "\n" ); document.write( "Answer:\r
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\n" ); document.write( "\n" ); document.write( "So the only solution is \"x+=+7\"
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