document.write( "Question 996754: Ompong is three years younger than VongFong. Six years ago, Ompong's age was two-thirds of VongFong's age. What are their present ages? \n" ); document.write( "
Algebra.Com's Answer #615167 by Theo(13342)![]() ![]() You can put this solution on YOUR website! x = ompong's age today. \n" ); document.write( "y = vongfong's age today.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "ompong is 3 years younger than vongfong.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "x = y - 3\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "six years ago, ompong's age was 2/3 of vongfong's age.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "x - 6 = 2/3 * (y - 6).\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "what are their present ages?\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "you have two equations to solve simultaneously.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "they are x = y - 3 (first equation) and x - 6 = 2/3 * (y - 6) (second equation).\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "simplify the second equation to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "x-6 = 2/3(y-6) becomes x-6 = 2/3 * y - 2/3 * 6\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "simplify further to get x-6 = 2/3 * y - 4.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the first equation tells you that x = y - 3.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "you can replace x with y - 3 in the second equation because they are equivalent.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "replace x in the second equation with (y - 3) to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "(y - 3) - 6 = 2/3 * y - 4.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "simplify to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "y - 9 = 2/3 * y - 4\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "add 9 to both sides of this equation to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "y = 2/3 * y + 5\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "subtract 2/3 * y from both sides of this equation to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "1/3 * y = 5\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "multiply both sides of this equation by 3 to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "y = 15\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "if y = 15, then x must be equal to 12 because x = y - 3.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "you have x = 12 and y = 15.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "that's their ages today.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "ompong is 12. \n" ); document.write( "vongfong is 15.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "six years ago ompong was 6 and vongfong was 9.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "6 is equal to 2/3 * 9.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "solution looks good.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "present ages of ompong and vongfong are 12 and 15.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |