document.write( "Question 82606: The sum of the digits of a two-digit counting number was 11. When the digits were reversed, the new number was 10 more than one-half the original number. What was the original number? \n" ); document.write( "
Algebra.Com's Answer #59200 by ankor@dixie-net.com(22740) You can put this solution on YOUR website! Let x = the 10's digit; let y = the units digit \n" ); document.write( ": \n" ); document.write( "\"The sum of the digits of a two-digit counting number was 11.\" \n" ); document.write( " x + y = 11 \n" ); document.write( "or x = (11 - y) \n" ); document.write( ": \n" ); document.write( "\"When the digits were reversed, the new number was 10 more than one-half the original number.\" \n" ); document.write( " 10y + x = .5(10x + y) + 10 \n" ); document.write( ": \n" ); document.write( "What was the original number? \n" ); document.write( ": \n" ); document.write( "10y + x = .5(10x + y) + 10 \n" ); document.write( "10y + x = 5x + .5y + 10 \n" ); document.write( "10y -.5y = 5x - x + 10 \n" ); document.write( "9.5y = 4x + 10\r \n" ); document.write( "\n" ); document.write( "replace x with (11-y) \n" ); document.write( "9.5y = 4(11-y) + 10 \n" ); document.write( "9.5y = 44 - 4y + 10 \n" ); document.write( "9.5y + 4y = 54 \n" ); document.write( "13.5y = 54 \n" ); document.write( "y = 54/13.5 \n" ); document.write( "y = 4 \n" ); document.write( ": \n" ); document.write( "find x: \n" ); document.write( "x = 11-y \n" ); document.write( "x = 11-4 \n" ); document.write( "x = 7 \n" ); document.write( ": \n" ); document.write( "The number: 74 \n" ); document.write( ": \n" ); document.write( ": \n" ); document.write( "Check using: \n" ); document.write( "\"When the digits were reversed, the new number was 10 more than one-half the original number.\" \n" ); document.write( " 47 = .5(74) + 10 \n" ); document.write( " 47 = 37 + 10 \n" ); document.write( " \n" ); document.write( " |