![\"\"](\"/images/stars/stars-13.gif\")
You can put this solution on YOUR website!
The price of a pen mistakenly had its two digits reversed so that a customer was over charged 18 cents.
\n" ); document.write( " If the sum of the digits is 16. Determine the correct price of the pen.
\n" ); document.write( ":
\n" ); document.write( "let x = the 10 digit of the correct price
\n" ); document.write( "let y = the units
\n" ); document.write( "then
\n" ); document.write( "10x+y = the correct price
\n" ); document.write( "and
\n" ); document.write( "10y+x = the incorrect price which 18 cents more
\n" ); document.write( ":
\n" ); document.write( "\"the sum of the digits is 16\", therefore
\n" ); document.write( "x + y = 16
\n" ); document.write( ":
\n" ); document.write( "the equation for this situation:
\n" ); document.write( "10x+y = 10y+x - 18
\n" ); document.write( "Combine like terms
\n" ); document.write( "10x - x = 10y - y - 18
\n" ); document.write( "9x = 9y - 18
\n" ); document.write( "simplify, divide thru by 9, results:
\n" ); document.write( "x = y - 2
\n" ); document.write( ":
\n" ); document.write( "In the sum of the digits equation, replace x with (y-2)
\n" ); document.write( "y - 2 + y = 16
\n" ); document.write( "2y = 16 + 2
\n" ); document.write( "2y = 18
\n" ); document.write( "y = 9 is the units digit
\n" ); document.write( "then
\n" ); document.write( "16 - 9 = 7 is the 10's digit
\n" ); document.write( ":
\n" ); document.write( "The correct price: 79 cents
\n" ); document.write( ":
\n" ); document.write( "Check this
\n" ); document.write( "The incorrect price: 97 cents which is 18 cents more \n" ); document.write( "