document.write( "Question 277285: The sum of the digits of a two- digit number is 14. When the digits are reversed, the new number is 36 more than the original number. What is the original number? \n" ); document.write( "
Algebra.Com's Answer #201930 by oberobic(2304)![]() ![]() ![]() You can put this solution on YOUR website! When solving number problems like these, we have to keep in mind the place values. \n" ); document.write( "For example, the number 23 actually means 2*10 + 3*1. \n" ); document.write( "Since the numbers are unknown in this word problem, we can call them 'xy'. \n" ); document.write( "BUT keep in mind that they are just standing next to each other, they're not being multiplied. \n" ); document.write( "The value would be 10x + y. \n" ); document.write( ". \n" ); document.write( "We are told some characteristics of the number 'xy'... \n" ); document.write( "x + y = 14 \n" ); document.write( ". \n" ); document.write( "That's easy, but the second statement is harder to set up. \n" ); document.write( ". \n" ); document.write( "Remember, the VALUE of 'xy' is 10x + y. \n" ); document.write( "So, reversing the digits to be 'yx' would change the VALUE to 10y + x. \n" ); document.write( ". \n" ); document.write( "We're told \n" ); document.write( "10y + x is 36 more than 10x + y, which algebraically is \n" ); document.write( "10y+x = 10x+y+36 \n" ); document.write( ". \n" ); document.write( "Rearranging this equation we have: \n" ); document.write( "x + 10y = 10x + y + 36 \n" ); document.write( "x -10x + 10y - y = 36 \n" ); document.write( "-9x + 9y = 36 \n" ); document.write( "dividing by 9 \n" ); document.write( "-x + y = 4 \n" ); document.write( ". \n" ); document.write( "Now we have to the two equations \n" ); document.write( "x + y = 14 \n" ); document.write( "-x + y = 4 \n" ); document.write( ". \n" ); document.write( "Adding we obtain \n" ); document.write( "2y = 18 \n" ); document.write( "y = 9 \n" ); document.write( ". \n" ); document.write( "Since x+y = 14, then x = 14-9 = 5 \n" ); document.write( ". \n" ); document.write( "Checking... \n" ); document.write( "xy = 59 \n" ); document.write( ". \n" ); document.write( "yx = 95 \n" ); document.write( ". \n" ); document.write( "Is 95 = 59 + 36?? \n" ); document.write( "Yes. \n" ); document.write( ". \n" ); document.write( "Answer: \n" ); document.write( "The original number was 59. \n" ); document.write( ". \n" ); document.write( "Done \n" ); document.write( " |