document.write( "Question 183093: 2x²-x=15 \n" ); document.write( "
Algebra.Com's Answer #137481 by jim_thompson5910(35256)\"\" \"About 
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\n" ); document.write( "\n" ); document.write( "\"2x%5E2-x=15\" Start with the given equation.\r
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\n" ); document.write( "\n" ); document.write( "\"2x%5E2-x-15=0\" Subtract 15 from both sides.\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=2\", \"b=-1\", 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-%28-1%29+%2B-+sqrt%28+%28-1%29%5E2-4%282%29%28-15%29+%29%29%2F%282%282%29%29\" Plug in \"a=2\", \"b=-1\", and \"c=-15\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%281+%2B-+sqrt%28+%28-1%29%5E2-4%282%29%28-15%29+%29%29%2F%282%282%29%29\" Negate \"-1\" to get \"1\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%281+%2B-+sqrt%28+1-4%282%29%28-15%29+%29%29%2F%282%282%29%29\" Square \"-1\" to get \"1\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%281+%2B-+sqrt%28+1--120+%29%29%2F%282%282%29%29\" Multiply \"4%282%29%28-15%29\" to get \"-120\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%281+%2B-+sqrt%28+1%2B120+%29%29%2F%282%282%29%29\" Rewrite \"sqrt%281--120%29\" as \"sqrt%281%2B120%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%281+%2B-+sqrt%28+121+%29%29%2F%282%282%29%29\" Add \"1\" to \"120\" to get \"121\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%281+%2B-+sqrt%28+121+%29%29%2F%284%29\" Multiply \"2\" and \"2\" to get \"4\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%281+%2B-+11%29%2F%284%29\" Take the square root of \"121\" to get \"11\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%281+%2B+11%29%2F%284%29\" or \"x+=+%281+-+11%29%2F%284%29\" Break up the expression. \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%2812%29%2F%284%29\" or \"x+=++%28-10%29%2F%284%29\" Combine like terms. \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+3\" or \"x+=+-5%2F2\" Simplify. \r
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\n" ); document.write( "\n" ); document.write( "So the answers are \"x+=+3\" or \"x+=+-5%2F2\" \r
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