document.write( "Question 187799: Graph both equations of eah system on the same coordinate axes. Use elimination of variables to find all pts of intersection.\r
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\n" ); document.write( "\n" ); document.write( "y = x^2 + 5x + 6
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Algebra.Com's Answer #140806 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
To perform elimination, simply subtract equation 2 from equation 1 to get\r
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\n" ); document.write( "\n" ); document.write( "\"y-y=%28x%5E2+%2B+5x+%2B+6%29-%28x%2B11%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"0=x%5E2+%2B+5x+%2B+6-x-11\"\r
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\n" ); document.write( "\n" ); document.write( "\"0=x%5E2%2B4x-5\"\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=4\", and \"c=-5\"\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-%284%29+%2B-+sqrt%28+%284%29%5E2-4%281%29%28-5%29+%29%29%2F%282%281%29%29\" Plug in \"a=1\", \"b=4\", and \"c=-5\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-4+%2B-+sqrt%28+16-4%281%29%28-5%29+%29%29%2F%282%281%29%29\" Square \"4\" to get \"16\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-4+%2B-+sqrt%28+16--20+%29%29%2F%282%281%29%29\" Multiply \"4%281%29%28-5%29\" to get \"-20\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-4+%2B-+sqrt%28+16%2B20+%29%29%2F%282%281%29%29\" Rewrite \"sqrt%2816--20%29\" as \"sqrt%2816%2B20%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-4+%2B-+sqrt%28+36+%29%29%2F%282%281%29%29\" Add \"16\" to \"20\" to get \"36\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-4+%2B-+sqrt%28+36+%29%29%2F%282%29\" Multiply \"2\" and \"1\" to get \"2\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-4+%2B-+6%29%2F%282%29\" Take the square root of \"36\" to get \"6\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-4+%2B+6%29%2F%282%29\" or \"x+=+%28-4+-+6%29%2F%282%29\" Break up the expression. \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%282%29%2F%282%29\" or \"x+=++%28-10%29%2F%282%29\" Combine like terms. \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+1\" or \"x+=+-5\" Simplify. \r
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\n" ); document.write( "\n" ); document.write( "So the answers are \"x+=+1\" or \"x+=+-5\" \r
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\n" ); document.write( "\n" ); document.write( "Now plug these values back into either equation (I'm going to use the second)\r
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\n" ); document.write( "\n" ); document.write( "Plug in \"x=1\"\r
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\n" ); document.write( "\n" ); document.write( "\"y=x%2B11=1%2B11=12\"\r
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\n" ); document.write( "\n" ); document.write( "So the first intersection is (1,12)\r
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\n" ); document.write( "\n" ); document.write( "Plug in \"x=-5\"\r
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\n" ); document.write( "\n" ); document.write( "\"y=x%2B11=-5%2B11=6\"\r
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\n" ); document.write( "\n" ); document.write( "So the second intersection is (-5,6)\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 \r
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\n" ); document.write( "\n" ); document.write( "\"x=1\" and \"y=12\" which gives the ordered pair (1,12)\r
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\n" ); document.write( "\n" ); document.write( "OR\r
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\n" ); document.write( "\n" ); document.write( "\"x=-5\" and \"y=6\" which gives the ordered pair (-5,6)\r
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\n" ); document.write( "\n" ); document.write( "Here's the graph to visually confirm the answer:\r
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\n" ); document.write( "\n" ); document.write( " Graph of \"y+=+x%5E2+%2B+5x+%2B+6\" and \"y=x%2B11\"
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