document.write( "Question 1121667: I don't know how to start this.
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document.write( "2/x+3 - 1/x+1 < 0 \n" );
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Algebra.Com's Answer #737625 by Theo(13342)![]() ![]() You can put this solution on YOUR website! 2/(x+3) - 1/(x+1) < 0\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "this function is undefined when x = -3 and when x = -1.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "this function is equal to 0 when x = 1.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "to solve for that, set the function equal to 0.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "you get 2/(x+3) - 1/(x+1) = 0\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "multiply both sides of the equiation by (x+3) * (x+1) to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "2 * (x+1) - (x + 3) = 0\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "simplify to get 2x + 2 - x - 3 = 0\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "combine like terms to get x - 1 = 0\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "solve for x to get x = 1\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "you have 4 intervals that need to be checked.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "they are:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "x < -3 \n" ); document.write( "x between -3 and -1 \n" ); document.write( "x between -1 and 1 \n" ); document.write( "x > 1\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the function is continuous between these intervals. \n" ); document.write( "therefore, within each interval, if it is greater than 0, it stays greater than 0 and, if it is less than 0, it says less than 0.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "it can only go from positive to negative at either side of the vertical asymptotes or when x = 1.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the function is 2/(x+3) - 1/(x+1) < 0\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "when x = -4, the function is 2/-1 - 1/-3 = -2 + 1/3 = less than 0.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "when x = -2, the function is 2/1 - 1/-1 = 2 + 1 = greater than 0.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "when x = 0, the function is 2/3 - 1 = less than 0.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "when x = 2, the function is 2/5 - 1/3 = greater than 0.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "it appears that the function is less than 0 when x < -3 and when x is between -1 and 1.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the following graph confirms that.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " ![]() \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |