document.write( "Question 1071471: solving age word problems (if mom + dad age now = 6 times the kids age, before 2 years mom + dad age = 10 times the kids age, after 6 years from now the age of mom + dad = 3 times the total of kids age. how many kids? total age mom and dad now? total kids age?) \n" ); document.write( "
Algebra.Com's Answer #686427 by Theo(13342)![]() ![]() You can put this solution on YOUR website! let x = the age of mom and dad today. \n" ); document.write( "let y = the age of the kids today.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "your equations are:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "x = 6y \n" ); document.write( "x-2 = 10 * (y-2) \n" ); document.write( "x+6 = 3 * (y+6)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "in order to solve this, all equations must have a common solution. \n" ); document.write( "unfortunately they don't.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "if you solve for a common solution for the first 2 equations, you will get: \n" ); document.write( "x = 27 and y = 4.5\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "if you solve for a common solution for the first and third equation, you will get: \n" ); document.write( "x = 24 and y = 4\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "if you solve for a common solution for the last 2 equations, you will get: \n" ); document.write( "x = 24.857 and y = 4.286\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "this means that you have no common solution for all 3 equations, therefore you have no solution.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "this can be seen graphically below:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " ![]() \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "x-6y is the red equation and red line on the graph. \n" ); document.write( "x-2 = 10 * (6-2) is the blue equation and blue line on the graph. \n" ); document.write( "x+6 = 3 * (6+6) is the green equation and green line on the graph.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "there is a common solution between red and blue. \n" ); document.write( "there is a common solution between red and green. \n" ); document.write( "therr is a common solution between blue and green.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "but, there is not a common solution between all 3.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "a common solution to all 3 equations cannot be found, therefore there is no solution.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "one of those equations is not being presented correctly.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "for example, assume 24 and 4 needed to be the answer.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "first equation is ok because 24 = 6 * 4. \n" ); document.write( "third equation is ok because 30 = 3 * 10 \n" ); document.write( "second equation is not ok.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "in order for second equation to be ok, let x = 24 and let y = 4 and evaluate the equation as is: \n" ); document.write( "you will get 24 - 2 = 10 * (y-2). \n" ); document.write( "this becomes 22 = 10 * (2) \n" ); document.write( "you will get 22 = 20 which is not correct. \n" ); document.write( "look at the ages today. \n" ); document.write( "x = 24 and y = 4 \n" ); document.write( "2 years ago, x = 22 and y = 2 \n" ); document.write( "this makes x equal to 11 * 2. \n" ); document.write( "the equaton should be: \n" ); document.write( "x-2 = 11 * (y-2) \n" ); document.write( "now, when you replace x with 24 and y with 4, you get: \n" ); document.write( "22 = 11 * 2 which becomes 22 = 22 which is correct.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "so, one of the equations is not in synch with the other equations. \n" ); document.write( "not sure which one, but one of them is definitely off. \n" ); document.write( "check your inputs to see that you got them correctly. \n" ); document.write( "if so, then there is no solution common to all 3 equations.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "another problem is interpretation. \n" ); document.write( "if the sum of the parents age is 24, then they must have been very young. \n" ); document.write( "too young, in fact, to have children. \n" ); document.write( "you could have been talking about their average age. \n" ); document.write( "in this case, everything would be doubled and you would wind up with the same problem if you assume 2 parents and 2 children.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "all in all, you have a pretty messed up problem here. \n" ); document.write( "there is no common solution as it is presented. \n" ); document.write( "it does not make sense unless there is more information available that is not presented.\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |