document.write( "Question 115423: Solve each of the following quadratic equations by completing the square.
\n" ); document.write( "2x2 + 10x + 11 = 0
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Algebra.Com's Answer #83996 by jim_thompson5910(35256)\"\" \"About 
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\"2x%5E2%2B10x%2B11=0\" Start with the given equation\r
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\n" ); document.write( "\n" ); document.write( "\"2x%5E2%2B10x=-11\" Subtract 11 from both sides
\n" ); document.write( "\"2%28x%5E2%2B5x%29=-11\" Factor out the leading coefficient 2. This step is important since we want the \"x%5E2\" coefficient to be equal to 1.\r
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\n" ); document.write( "\n" ); document.write( "Take half of the x coefficient 5 to get \"5%2F2\"\r
\n" ); document.write( "\n" ); document.write( "Now square \"5%2F2\" to get \"25%2F4\"\r
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\n" ); document.write( "\n" ); document.write( "\"2%28x%5E2%2B5x%2B25%2F4%29=-11%2B%2825%2F4%29%282%29\" Add this result \"25%2F4\" to the expression \"x%5E2%2B5x\" inside the parenthesis. Now the expression \"x%5E2%2B5x%2B25%2F4\" is a perfect square trinomial. Now add the result \"%2825%2F4%29%282%29\" (remember we factored out a 2) to the right side.\r
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\n" ); document.write( "\n" ); document.write( "\"2%28x%2B5%2F2%29%5E2=-11%2B%2825%2F4%29%282%29\" Factor \"x%5E2%2B5x%2B25%2F4\" into \"%28x%2B5%2F2%29%5E2\" \r
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\n" ); document.write( "\n" ); document.write( "\"2%28x%2B5%2F2%29%5E2=-11%2B25%2F2\" Multiply \"25%2F4\" and 2 to get \"25%2F2\"\r
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\n" ); document.write( "\n" ); document.write( "\"2%28x%2B5%2F2%29%5E2=3%2F2\" Combine like terms on the right side\r
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\n" ); document.write( "\n" ); document.write( "\"%28x%2B5%2F2%29%5E2=3%2F4\" Divide both sides by 2\r
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\n" ); document.write( "\n" ); document.write( "\"x%2B5%2F2=0%2B-sqrt%283%2F4%29\" Take the square root of both sides\r
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\n" ); document.write( "\n" ); document.write( "\"x%2B5%2F2=0%2B-sqrt%283%29%2Fsqrt%284%29\" Break up the square root\r
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\n" ); document.write( "\n" ); document.write( "\"x%2B5%2F2=0%2B-sqrt%283%29%2F2\" Take the square root of 4 to get 2\r
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\n" ); document.write( "\n" ); document.write( "\"x=-5%2F2%2B-sqrt%283%29%2F2\" Subtract \"5%2F2\" from both sides to isolate x.\r
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\n" ); document.write( "\n" ); document.write( "\"x=%28-5%2B-sqrt%283%29%29%2F2\" Combine the fractions\r
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\n" ); document.write( "\n" ); document.write( "So our answer is \r
\n" ); document.write( "\n" ); document.write( "\"x=%28-5%2Bsqrt%283%29%29%2F2\" or \"x=%28-5-sqrt%283%29%29%2F2\" \r
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