document.write( "Question 1054978: In a number of two digits, the sum of the digits is 14. If the digits are interchanged, the resulting number is 18 less than the original number. Find the number. \n" ); document.write( "
Algebra.Com's Answer #670194 by Theo(13342)![]() ![]() You can put this solution on YOUR website! let x equal the first digit of the original number. \n" ); document.write( "let y equal the second digit of the original number.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the original number is equal to 10x + y.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "if you reverse the digits, then the number with the digits reversed is equal to 10y + x.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "x + y = 14\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "10x + y = 10y + x - 18\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( "9x - 9y = -18\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "solve for x in the first equation to get x = 14 - y\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "replace x with 14 - y in the second equation to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "9 * (14 - y) - 9y = -18\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "simplify to get 126 - 9y - 9y = -18\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "combine like terms to get 126 - 18y = -18\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "add 18 to both sides of the equation and add 18y to both sides of the equation to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "126 + 18 = 18y\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "combine like terms to get 144 = 18y\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "divide both sides of the equation by 18 to get 144/18 = y\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "simplify to get 8 = y\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "since x + y = 14, then x must be equal to 6.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "x + y = 14 becomes 14 = 14 which is true.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "10x + y = 10y + x - 18 becomes 60 + 8 = 80 + 6 - 18 which becomes 68 = 86 - 18 which becomes 68 = 68 which is true.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the original number is 10x + y which is equal to 68.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the number with the digits reversed is equal to 10y + x which is equal to 86.\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |