document.write( "Question 684020: the sum of a two-digit number is 9. the number with the digits interchanged is 6 times the sum of the digits. find the original number \n" ); document.write( "
Algebra.Com's Answer #423974 by ankor@dixie-net.com(22740)\"\" \"About 
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the sum of a two-digit number is 9. the number with the digits interchanged is 6 times the sum of the digits. find the original number
\n" ); document.write( ":
\n" ); document.write( "Let x = the 10's digit
\n" ); document.write( "Let y = the units
\n" ); document.write( "then
\n" ); document.write( "10x+y = the original number
\n" ); document.write( ":
\n" ); document.write( "\" the sum of a two-digit number is 9.\"
\n" ); document.write( "x + y = 9
\n" ); document.write( ":
\n" ); document.write( "\"the number with the digits interchanged is 6 times the sum of the digits.\"
\n" ); document.write( "10y + x = 6(x + y)
\n" ); document.write( "therefore
\n" ); document.write( "10y + x = 6(9)
\n" ); document.write( "10y + x = 54
\n" ); document.write( ":
\n" ); document.write( "Arrange to use elimination
\n" ); document.write( "x + 10y = 54
\n" ); document.write( "x + y = 9
\n" ); document.write( "-----------------subtraction eliminates x, find y
\n" ); document.write( "9y = 45
\n" ); document.write( "y = 45/9
\n" ); document.write( "y = 5
\n" ); document.write( ":
\n" ); document.write( "Find x
\n" ); document.write( "x + 5 = 9
\n" ); document.write( "x = 4
\n" ); document.write( ":
\n" ); document.write( "Find the original number: 45 \n" ); document.write( "
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