document.write( "Question 893067: The sum of the digits of a two digit number is 9. If 9 is added to the number, then the digits are reversed.Find the number. \n" ); document.write( "
Algebra.Com's Answer #541223 by AnlytcPhil(1806)![]() ![]() You can put this solution on YOUR website! \r\n" ); document.write( "Let the number be XY. Then when you add 9 you have this:\r\n" ); document.write( "\r\n" ); document.write( " XY\r\n" ); document.write( " + 9\r\n" ); document.write( " ----\r\n" ); document.write( " YX\r\n" ); document.write( "\r\n" ); document.write( "9 is so large that when you add 9 to Y you are bound to have to carry 1. \r\n" ); document.write( "So let's put a 1 to carry above the X in the left column:\r\n" ); document.write( "\r\n" ); document.write( " 1\r\n" ); document.write( " XY\r\n" ); document.write( " + 9\r\n" ); document.write( " ----\r\n" ); document.write( " YX\r\n" ); document.write( "\r\n" ); document.write( " The 1 to carry shows that Y is 1 more than X, so do a little trial and error:\r\n" ); document.write( "\r\n" ); document.write( "Is X 1 and Y 2? No because 1+2 isn't 9.\r\n" ); document.write( "\r\n" ); document.write( " 1\r\n" ); document.write( " 12\r\n" ); document.write( " + 9\r\n" ); document.write( " ----\r\n" ); document.write( " 21\r\n" ); document.write( "\r\n" ); document.write( "But the digits are reversed.\r\n" ); document.write( "\r\n" ); document.write( "Is X 2 and Y 3? No because 2+3 isn't 9.\r\n" ); document.write( "\r\n" ); document.write( " 1\r\n" ); document.write( " 23\r\n" ); document.write( " + 9\r\n" ); document.write( " ----\r\n" ); document.write( " 32\r\n" ); document.write( "\r\n" ); document.write( "But the digits are reversed.\r\n" ); document.write( "\r\n" ); document.write( "Is X 3 and Y 4? No because 3+4 isn't 9.\r\n" ); document.write( "\r\n" ); document.write( " 1\r\n" ); document.write( " 34\r\n" ); document.write( " + 9\r\n" ); document.write( " ----\r\n" ); document.write( " 43\r\n" ); document.write( "\r\n" ); document.write( "But the digits are reversed.\r\n" ); document.write( "\r\n" ); document.write( "Is X 4 and Y 5? 4+5=9. HEY! RIGHT\r\n" ); document.write( "\r\n" ); document.write( " 1\r\n" ); document.write( " 45\r\n" ); document.write( " + 9\r\n" ); document.write( " ----\r\n" ); document.write( " 54\r\n" ); document.write( "\r\n" ); document.write( "And the digits are reversed. HEY! THAT'S IT!!!!\r\n" ); document.write( "\r\n" ); document.write( "Phil\n" ); document.write( " |