document.write( "Question 958974: The product of Hanny's and younger brother Robert's ages is 135. When their ages are divided, the quotient is 1 and the remainder is 6. How old are they now? \n" ); document.write( "
Algebra.Com's Answer #586099 by Theo(13342)![]() ![]() You can put this solution on YOUR website! let h = hanny's age. \n" ); document.write( "let r = robert's age. \n" ); document.write( "h*r = 135 \n" ); document.write( "h/r = 1 + remainder of 6.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "you could use trial and error and you would get the following:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "135 has to be divisible by 5 because the factors have to be integers.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "this is not really stated, but i think it's implied.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "whether this assumption is valid or not, it does lead to an answer that is corroborated by the more advanced solution to come later.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "looking for the two factors that, when multiplied together, equal 135 yields the following.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "135/5 = 27, so 5 * 27 = 135 but 27/5 doesn't have a quotient of 1, so these factors don't work.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "135 / 10 = 13.5, so 13.5 * 10 = 135, and 13.5 / 10 give you a quotient of 1 but not a remainder of 6, these factors don't work..\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "135 / 15 = 9, so 15 * 9 = 135, and 15/9 = 1 with a remainder of 6, so this looks like the one.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "hanny is 15 and roberto is 9 looks like your solution.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "now for the more advanced way to solve it.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "you have h * r = 135\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "you also have h / r = 1 + remainder of 6, which can also be shown as:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "h/r = 1 + (6/r)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "you have:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "h*r = 135 \n" ); document.write( "h/r = 1 + (6/r)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "in the second equation of h/r = 1 + (6/r), solve for h to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "h = (1 + 6/r) * r which simplifies to:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "h = (r + 6)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "in the first equation of h*r = 135, replace h with (r + 6) to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "(r + 6)*r = 135\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "simplify to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "r^2 + 6r = 135\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "subtract 135 from both sides of the equation to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "r^2 + 6r - 135 = 0\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "factor this equation to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "(r + 15) * (r - 9) = 0\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "solve for r to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "r = -15 or r = 9\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "r can't be negative, so r must be equal to 9.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the original equation of h*r = 135 can now be solved for h.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "this results in h = 15.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the solution is h = 15 and r = 9.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "both methods get the same solution so it looks good.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |