document.write( "Question 280832: The sum of the digits of a two digit number is 14. If 36 is subtracted from the number, the resulting number is the original number with its digits interchangeable. Find the Number. \n" ); document.write( "
Algebra.Com's Answer #204089 by oberobic(2304)![]() ![]() ![]() You can put this solution on YOUR website! When doing sum of digits problems, you have to remember that numbers like 'xy' are not being multiplied. \n" ); document.write( "Consider the number 23. \n" ); document.write( "It really is not \"one\" number, but instead it means 2*10 + 3*1. \n" ); document.write( ". \n" ); document.write( "So the number is 'xy' but that is NOT x*y, it's just 'x' next to 'y'. \n" ); document.write( "The value of the number 'xy' = 10x + y. \n" ); document.write( ". \n" ); document.write( "x + y = 14 :: given \n" ); document.write( ". \n" ); document.write( "36 is a value, so to subtract it, you have to calculate the value of xy: \n" ); document.write( ". \n" ); document.write( "10x+y -36 = 10y + x \n" ); document.write( ". \n" ); document.write( "Setting up a system of equations: \n" ); document.write( ". \n" ); document.write( "10x + y - 36 - 10y - x = 0 \n" ); document.write( "9x - 9y = 36 \n" ); document.write( "x - y = 4 \n" ); document.write( ". \n" ); document.write( "x + y = 14 \n" ); document.write( "x - y = 4 \n" ); document.write( ". \n" ); document.write( "adding \n" ); document.write( ". \n" ); document.write( "2x = 18 \n" ); document.write( "x = 9 \n" ); document.write( ". \n" ); document.write( "x + y = 14 \n" ); document.write( "given x = 9 \n" ); document.write( "y = 5 \n" ); document.write( ". \n" ); document.write( "so the original number, 'xy', appears to be 95. \n" ); document.write( ". \n" ); document.write( "checking... \n" ); document.write( "'yx' would be 59. \n" ); document.write( ". \n" ); document.write( "so, is 95 - 36 = 59? \n" ); document.write( "Yes, it is. \n" ); document.write( ". \n" ); document.write( "Answer: \n" ); document.write( "The number is 95. \n" ); document.write( ". \n" ); document.write( "Done. \n" ); document.write( " |