document.write( "Question 263181: Find the root of the quadratic equation x^2-8x+15=0 \n" ); document.write( "
Algebra.Com's Answer #193947 by jim_thompson5910(35256)\"\" \"About 
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\n" ); document.write( "\n" ); document.write( "\"x%5E2-8x%2B15=0\" Start with the given equation.\r
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\n" ); document.write( "\n" ); document.write( "Notice that the quadratic \"x%5E2-8x%2B15\" is in the form of \"Ax%5E2%2BBx%2BC\" where \"A=1\", \"B=-8\", and \"C=15\"\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-%28-8%29+%2B-+sqrt%28+%28-8%29%5E2-4%281%29%2815%29+%29%29%2F%282%281%29%29\" Plug in \"A=1\", \"B=-8\", and \"C=15\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%288+%2B-+sqrt%28+%28-8%29%5E2-4%281%29%2815%29+%29%29%2F%282%281%29%29\" Negate \"-8\" to get \"8\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%288+%2B-+sqrt%28+64-4%281%29%2815%29+%29%29%2F%282%281%29%29\" Square \"-8\" to get \"64\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%288+%2B-+sqrt%28+64-60+%29%29%2F%282%281%29%29\" Multiply \"4%281%29%2815%29\" to get \"60\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%288+%2B-+sqrt%28+4+%29%29%2F%282%281%29%29\" Subtract \"60\" from \"64\" to get \"4\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%288+%2B-+sqrt%28+4+%29%29%2F%282%29\" Multiply \"2\" and \"1\" to get \"2\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%288+%2B-+2%29%2F%282%29\" Take the square root of \"4\" to get \"2\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%288+%2B+2%29%2F%282%29\" or \"x+=+%288+-+2%29%2F%282%29\" Break up the expression. \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%2810%29%2F%282%29\" or \"x+=++%286%29%2F%282%29\" Combine like terms. \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+5\" or \"x+=+3\" Simplify. \r
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\n" ); document.write( "\n" ); document.write( "So the solutions are \"x+=+5\" or \"x+=+3\"
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