document.write( "Question 153544: Please help me solve the following problem:
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document.write( " Simplify the expression (x^2 - 9)/(x^2 + 3x)\r
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document.write( "My attempt to this problem was to cancel out the x^2 because they divided each other, and then i simplified -9/3x to -3x. But when i check to see if my work is correct by substituting x for 2, the answers did not match. \n" );
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Algebra.Com's Answer #113025 by stanbon(75887)![]() ![]() ![]() You can put this solution on YOUR website! Simplify the expression (x^2 - 9)/(x^2 + 3x)\r \n" ); document.write( "\n" ); document.write( "My attempt to this problem was to cancel out the x^2 because they divided each other, and then i simplified -9/3x to -3x. But when i check to see if my work is correct by substituting x for 2, the answers did not match. \n" ); document.write( "--------------- \n" ); document.write( "You may only cancel \"factors\" that are common to the numerator and to the \n" ); document.write( "denominator. \n" ); document.write( "x^2 is a \"term\" in the numerator and a \"term\" in the denominator and \n" ); document.write( "may not be cancelled. \n" ); document.write( "Example (2 + 3)/(2 + 5) \n" ); document.write( "If you cancelled the \"2\" you would get 3/5; but the answer should be 5/7. \n" ); document.write( "Don't cancel terms. \n" ); document.write( "------------------------ \n" ); document.write( "Simplify the expression (x^2 - 9)/(x^2 + 3x) \n" ); document.write( "Factor where you can to get: \n" ); document.write( "[(x-3)(x+3)] / [x(x + 3)] \n" ); document.write( "Notice that the (x+3) is a factor of the numberator and of the denominator \n" ); document.write( "so you may cancel it to get: \n" ); document.write( " = (x-3)/(x) \n" ); document.write( "Notice that you cannot cancel the \"x\" because it is a \"term\" and not a factor in the numerator. \n" ); document.write( "=============== \n" ); document.write( "Cheers, \n" ); document.write( "Stan H.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |