document.write( "Question 157979: 1 Solve by completing the square
\n" ); document.write( " X^2 + 10x +13 = 0\r
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\n" ); document.write( " X^2 - 2x = 5x-2\r
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\n" ); document.write( " x^2 - 3x - 3 = -5
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Algebra.Com's Answer #116402 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
I'll do the first two to get you started\r
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\n" ); document.write( "\n" ); document.write( "\"x%5E2%2B10x%2B13\" Start with the given expression.\r
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\n" ); document.write( "\n" ); document.write( "Take half of the \"x\" coefficient \"10\" to get \"5\". In other words, \"%281%2F2%29%2810%29=5\".\r
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\n" ); document.write( "\n" ); document.write( "Now square \"5\" to get \"25\". In other words, \"%285%29%5E2=%285%29%285%29=25\"\r
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\n" ); document.write( "\n" ); document.write( "\"x%5E2%2B10x%2Bhighlight%2825-25%29%2B13\" Now add and subtract \"25\". Make sure to place this after the \"x\" term. Notice how \"25-25=0\". So the expression is not changed.\r
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\n" ); document.write( "\n" ); document.write( "\"%28x%5E2%2B10x%2B25%29-25%2B13\" Group the first three terms.\r
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\n" ); document.write( "\n" ); document.write( "\"%28x%2B5%29%5E2-25%2B13\" Factor \"x%5E2%2B10x%2B25\" to get \"%28x%2B5%29%5E2\".\r
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\n" ); document.write( "\n" ); document.write( "\"%28x%2B5%29%5E2-12\" Combine like terms.\r
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\n" ); document.write( "\n" ); document.write( "So after completing the square, \"x%5E2%2B10x%2B13\" transforms to \"%28x%2B5%29%5E2-12\". So \"x%5E2%2B10x%2B13=%28x%2B5%29%5E2-12\".\r
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\n" ); document.write( "\n" ); document.write( "So \"x%5E2%2B10x%2B13=0\" is equivalent to \"%28x%2B5%29%5E2-12=0\".\r
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\n" ); document.write( "\n" ); document.write( "\"%28x%2B5%29%5E2-12=0\" Start with the given equation.\r
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\n" ); document.write( "\n" ); document.write( "\"%28x%2B5%29%5E2=0%2B12\"Add \"12\" to both sides.\r
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\n" ); document.write( "\n" ); document.write( "\"%28x%2B5%29%5E2=12\" Combine like terms.\r
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\n" ); document.write( "\n" ); document.write( "\"x%2B5=0%2B-sqrt%2812%29\" Take the square root of both sides.\r
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\n" ); document.write( "\n" ); document.write( "\"x%2B5=sqrt%2812%29\" or \"x%2B5=-sqrt%2812%29\" Break up the \"plus/minus\" to form two equations.\r
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\n" ); document.write( "\n" ); document.write( "\"x%2B5=2%2Asqrt%283%29\" or \"x%2B5=-2%2Asqrt%283%29\" Simplify the square root.\r
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\n" ); document.write( "\n" ); document.write( "\"x=-5%2B2%2Asqrt%283%29\" or \"x=-5-2%2Asqrt%283%29\" Subtract \"5\" from both sides.\r
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\n" ); document.write( "\n" ); document.write( "So the solutions are \"x=-5%2B2%2Asqrt%283%29\" or \"x=-5-2%2Asqrt%283%29\".\r
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\n" ); document.write( "\n" ); document.write( "\"x%5E2-2x=5x-2\" Start with the given equation.\r
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\n" ); document.write( "\n" ); document.write( "\"x%5E2-2x-5x%2B2=0\" Subtract \"5x\" from both sides. Add 2 to both sides.\r
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\n" ); document.write( "\n" ); document.write( "\"x%5E2-7x%2B2=0\" 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=-7\", and \"c=2\"\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-%28-7%29+%2B-+sqrt%28+%28-7%29%5E2-4%281%29%282%29+%29%29%2F%282%281%29%29\" Plug in \"a=1\", \"b=-7\", and \"c=2\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%287+%2B-+sqrt%28+%28-7%29%5E2-4%281%29%282%29+%29%29%2F%282%281%29%29\" Negate \"-7\" to get \"7\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%287+%2B-+sqrt%28+49-4%281%29%282%29+%29%29%2F%282%281%29%29\" Square \"-7\" to get \"49\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%287+%2B-+sqrt%28+49-8+%29%29%2F%282%281%29%29\" Multiply \"4%281%29%282%29\" to get \"8\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%287+%2B-+sqrt%28+41+%29%29%2F%282%281%29%29\" Subtract \"8\" from \"49\" to get \"41\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%287+%2B-+sqrt%28+41+%29%29%2F%282%29\" Multiply \"2\" and \"1\" to get \"2\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%287%2Bsqrt%2841%29%29%2F%282%29\" or \"x+=+%287-sqrt%2841%29%29%2F%282%29\" Break up the expression. \r
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\n" ); document.write( "\n" ); document.write( "So the answers are \"x+=+%287%2Bsqrt%2841%29%29%2F%282%29\" or \"x+=+%287-sqrt%2841%29%29%2F%282%29\" \r
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\n" ); document.write( "\n" ); document.write( "which approximate to \"x=6.702\" or \"x=0.298\"
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