document.write( "Question 171916: Solve by completing the square
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Algebra.Com's Answer #127015 by jim_thompson5910(35256)\"\" \"About 
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\n" ); document.write( "\n" ); document.write( "\"3x%5E2%2B5x-1\" Start with the left side of the equation.\r
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\n" ); document.write( "\n" ); document.write( "\"3%28x%5E2%2B%285%2F3%29x-1%2F3%29\" Factor out the \"x%5E2\" coefficient \"3\". This step is very important: the \"x%5E2\" coefficient must be equal to 1.\r
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\n" ); document.write( "\n" ); document.write( "Take half of the \"x\" coefficient \"5%2F3\" to get \"5%2F6\". In other words, \"%281%2F2%29%285%2F3%29=5%2F6\".\r
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\n" ); document.write( "\n" ); document.write( "Now square \"5%2F6\" to get \"25%2F36\". In other words, \"%285%2F6%29%5E2=%285%2F6%29%285%2F6%29=25%2F36\"\r
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\n" ); document.write( "\n" ); document.write( "\"3%28x%5E2%2B%285%2F3%29x%2Bhighlight%2825%2F36-25%2F36%29-1%2F3%29\" Now add and subtract \"25%2F36\" inside the parenthesis. Make sure to place this after the \"x\" term. Notice how \"25%2F36-25%2F36=0\". So the expression is not changed.\r
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\n" ); document.write( "\n" ); document.write( "\"3%28%28x%5E2%2B%285%2F3%29x%2B25%2F36%29-25%2F36-1%2F3%29\" Group the first three terms.\r
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\n" ); document.write( "\n" ); document.write( "\"3%28%28x%2B5%2F6%29%5E2-25%2F36-1%2F3%29\" Factor \"x%5E2%2B%285%2F3%29x%2B25%2F36\" to get \"%28x%2B5%2F6%29%5E2\".\r
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\n" ); document.write( "\n" ); document.write( "\"3%28%28x%2B5%2F6%29%5E2-37%2F36%29\" Combine like terms.\r
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\n" ); document.write( "\n" ); document.write( "\"3%28x%2B5%2F6%29%5E2%2B3%28-37%2F36%29\" Distribute.\r
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\n" ); document.write( "\n" ); document.write( "\"3%28x%2B5%2F6%29%5E2-37%2F12\" Multiply.\r
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\n" ); document.write( "\n" ); document.write( "So after completing the square, \"3x%5E2%2B5x-1\" transforms to \"3%28x%2B5%2F6%29%5E2-37%2F12\". So \"3x%5E2%2B5x-1=3%28x%2B5%2F6%29%5E2-37%2F12\".\r
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\n" ); document.write( "\n" ); document.write( "So \"3x%5E2%2B5x-1=0\" is equivalent to \"3%28x%2B5%2F6%29%5E2-37%2F12=0\".\r
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\n" ); document.write( "\n" ); document.write( "\"3%28x%2B5%2F6%29%5E2-37%2F12=0\" Start with the given equation.\r
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\n" ); document.write( "\n" ); document.write( "\"3%28x%2B5%2F6%29%5E2=0%2B37%2F12\"Add \"37%2F12\" to both sides.\r
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\n" ); document.write( "\n" ); document.write( "\"3%28x%2B5%2F6%29%5E2=37%2F12\" Combine like terms.\r
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\n" ); document.write( "\n" ); document.write( "\"%28x%2B5%2F6%29%5E2=%2837%2F12%29%2F%283%29\" Divide both sides by \"3\".\r
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\n" ); document.write( "\n" ); document.write( "\"%28x%2B5%2F6%29%5E2=37%2F36\" Reduce.\r
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\n" ); document.write( "\n" ); document.write( "\"x%2B5%2F6=0%2B-sqrt%2837%2F36%29\" Take the square root of both sides.\r
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\n" ); document.write( "\n" ); document.write( "\"x%2B5%2F6=sqrt%2837%2F36%29\" or \"x%2B5%2F6=-sqrt%2837%2F36%29\" Break up the \"plus/minus\" to form two equations.\r
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\n" ); document.write( "\n" ); document.write( "\"x%2B5%2F6=sqrt%2837%29%2F6\" or \"x%2B5%2F6=-sqrt%2837%29%2F6\" Simplify the square root.\r
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\n" ); document.write( "\n" ); document.write( "\"x=-5%2F6%2Bsqrt%2837%29%2F6\" or \"x=-5%2F6-sqrt%2837%29%2F6\" Subtract \"5%2F6\" from both sides.\r
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\n" ); document.write( "\n" ); document.write( "\"x=%28-5%2Bsqrt%2837%29%29%2F%286%29\" or \"x=%28-5-sqrt%2837%29%29%2F%286%29\" Combine the fractions.\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 solutions are \"x=%28-5%2Bsqrt%2837%29%29%2F%286%29\" or \"x=%28-5-sqrt%2837%29%29%2F%286%29\".
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