document.write( "Question 335938: Write the given expression f(x)= x^2+10x+7 in the form f(x)=a(x-h)^2+k. And identify the vertex \n" ); document.write( "
Algebra.Com's Answer #240926 by jim_thompson5910(35256)\"\" \"About 
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\n" ); document.write( "\"x%5E2%2B10x%2B7\" 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%2B7\" 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%2B7\" Group the first three terms.\r
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\n" ); document.write( "\n" ); document.write( "\"%28x%2B5%29%5E2-25%2B7\" 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%5E2-18\" Combine like terms.\r
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\n" ); document.write( "\n" ); document.write( "So after completing the square, \"x%5E2%2B10x%2B7\" transforms to \"%28x%2B5%29%5E2-18\". So \"x%5E2%2B10x%2B7=%28x%2B5%29%5E2-18\".\r
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\n" ); document.write( "\n" ); document.write( "This means that \"f%28x%29=x%5E2%2B10x%2B7\" is equivalent to \"f%28x%29=%28x%2B5%29%5E2-18\".\r
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\n" ); document.write( "\n" ); document.write( "So the equation \"f%28x%29=%28x%2B5%29%5E2-18\" is now in vertex form \"f%28x%29=a%28x-h%29%5E2%2Bk\" where \"a=1\", \"h=-5\", and \"k=-18\"\r
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\n" ); document.write( "\n" ); document.write( "Remember, the vertex of \"f%28x%29=a%28x-h%29%5E2%2Bk\" is (h,k).\r
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\n" ); document.write( "\n" ); document.write( "So the vertex of \"f%28x%29=%28x%2B5%29%5E2-18\" is (-5,-18) since h=-5 and k=-18 \r
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\n" ); document.write( "\n" ); document.write( "This means that the vertex of \"f%28x%29=x%5E2%2B10x%2B7\" is (-5,-18)\r
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\n" ); document.write( "\n" ); document.write( "If you need more help, email me at jim_thompson5910@hotmail.com\r
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\n" ); document.write( "\n" ); document.write( "Also, feel free to check out my website. \r
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\n" ); document.write( "\n" ); document.write( "Jim
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