document.write( "Question 49989: What am I supposed to do with this? Am I supposed to follow an order of operation?
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Algebra.Com's Answer #33226 by AnlytcPhil(1806)\"\" \"About 
You can put this solution on YOUR website!
What am I supposed to do with this? \r\n" );
document.write( "Am I supposed to follow an order of operation?\r\n" );
document.write( "I am having problems with this. Please help me.\r\n" );
document.write( "Find all the numbers for which the rational expression is undefined: \r\n" );
document.write( "a. (x+3)/[(x–2)(x+5)]\r\n" );
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document.write( "b. 7/(x²+81)\r\n" );
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document.write( "You're supposed to know that a fraction (rational expression) is undefined\r\n" );
document.write( "if its denominator is equal to 0.\r\n" );
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document.write( "So you set the denominator = 0 and find out what values will make the\r\n" );
document.write( "fraction undefined. You can ignore the numerator because it has no\r\n" );
document.write( "effect on whether a fraction (rational expression) is defined or\r\n" );
document.write( "undefined.\r\n" );
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document.write( "The denominator of (a.) is (x-2)(x+5)\r\n" );
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document.write( "So set (x-2)(x+5) equal to 0 and solve:\r\n" );
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document.write( "(x-2)(x+5) = 0\r\n" );
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document.write( "Set each factor = 0\r\n" );
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document.write( "x-2 = 0 gives x = 2\r\n" );
document.write( "x+5 = 0 gives x = -5\r\n" );
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document.write( "So 2 and -5 are the values which cause the \r\n" );
document.write( "fraction to be undefined.\r\n" );
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document.write( "The denominator in part (b.) is x²+81\r\n" );
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document.write( "We set x²+81 = 0\r\n" );
document.write( "          x² = -81\r\n" );
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document.write( "But if we take the square root of a negative\r\n" );
document.write( "number we do not get a real number. So there\r\n" );
document.write( "is no real solution to x²+81=0.  Therefore\r\n" );
document.write( "(b.) is never undefined.  \r\n" );
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document.write( "Edwin
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