document.write( "Question 1079813: NEED HELP .. Write a rational expression involving one variable for which the excluded values are -4 and -7. \n" ); document.write( "

Algebra.Com's Answer #694044 by Edwin McCravy(20065) $\"\"$ $\"About$

You can put this solution on YOUR website!

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document.write( "The dnominator of the rational expression has to be such that\r\n" );
document.write( "when either -4 or -7 is substituted for x, the denominator\r\n" );
document.write( "becomes zero.  So we find such a denominator we find a quadratic\r\n" );
document.write( "equation with solutions \r\n" );
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document.write( "    x = -4 and x = -7 \r\n" );
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document.write( "Get 0 on the right of each:\r\n" );
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document.write( "   x+4 = 0 and x+7 = 0\r\n" );
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document.write( "Now we multiply equals by equals,\r\n" );
document.write( "multiply left sides and multiply right sides:\r\n" );
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document.write( "  (x+4)(x+7) = (0)(0)\r\n" );
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document.write( "  (x+4)(x+7) = 0 \r\n" );
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document.write( "So that can be the denominator of such a rational \r\n" );
document.write( "function.  The numerator can be anything you choose:\r\n" );
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document.write( " or  or \r\n" );
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document.write( "or any numerator you want to make up, as long is it doesn't contain\r\n" );
document.write( "another variable besides x.  You can even multiply the denominator by\r\n" );
document.write( "any constant, like this\r\n" );
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document.write( "Edwin

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