document.write( "Question 387213: a two digit number is 11 times its units digit. The sum of the digits is 12. find the number \n" ); document.write( "
Algebra.Com's Answer #276078 by gwendolyn(128)\"\" \"About 
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Let X be the tens digit
\n" ); document.write( "Let Y be the units digit\r
\n" ); document.write( "\n" ); document.write( "The value of the two digit number is calculated as 10*X + Y, since X is the digit in the tens spot. Since this number is 11 times its units digit, then\r
\n" ); document.write( "\n" ); document.write( "10*X + Y = 11*Y
\n" ); document.write( "Subtract Y from both sides:
\n" ); document.write( "10*X + Y - Y = 11*Y - Y
\n" ); document.write( "10*X = 10*Y
\n" ); document.write( "Divide both sides by 10:
\n" ); document.write( "\"%2810%2AX%29%2F10+=+%2810%2AY%29%2F10\"
\n" ); document.write( "X = Y
\n" ); document.write( "(Which makes sense if you think about two-digit multiples of 11.)\r
\n" ); document.write( "\n" ); document.write( "The sum of the digits is 12, so:
\n" ); document.write( "X + Y = 12\r
\n" ); document.write( "\n" ); document.write( "Substitute the value of X from the first equation:
\n" ); document.write( "Y + Y = 12
\n" ); document.write( "2*Y = 12
\n" ); document.write( "Divide both sides by 2:\r
\n" ); document.write( "\n" ); document.write( "\"%282%2AY%29%2F2+=+12%2F2\"
\n" ); document.write( "Y = 6
\n" ); document.write( "Substitute in the first equation for X:
\n" ); document.write( "X = 6
\n" ); document.write( "So, the two-digit number is 66
\n" ); document.write( "
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