document.write( "Question 552276: if you multiply this even digit by itself, the sum of the digits of the product is 9. What is the mystery digit? \n" ); document.write( "
Algebra.Com's Answer #360201 by AnlytcPhil(1809)\"\" \"About 
You can put this solution on YOUR website!
\r\n" );
document.write( "The digits are 1,2,3,4,5,6,7,8,9,and 0\r\n" );
document.write( "\r\n" );
document.write( "The even ones are 0,2,4,6,8.  The odd ones are 1,3,5,7,9\r\n" );
document.write( "\r\n" );
document.write( "Let's try the even digit 0.\r\n" );
document.write( "\r\n" );
document.write( "0×0 = 0.  There is only one digit, so that can't be it.\r\n" );
document.write( "\r\n" );
document.write( "Let's try the even digit 2.\r\n" );
document.write( "\r\n" );
document.write( "2×2 = 4.  There is only one digit, so that can't be it either.\r\n" );
document.write( "\r\n" );
document.write( "Let's try the even digit 8.\r\n" );
document.write( "\r\n" );
document.write( "8×8 = 64.  Let's find the sum of the digits 6+4=10.  No, 10 is not 9,\r\n" );
document.write( "so it's not 8\r\n" );
document.write( "\r\n" );
document.write( "I skipped the even digit 6, didn't I?  \r\n" );
document.write( "\r\n" );
document.write( "Let's try the even digit 6\r\n" );
document.write( "\r\n" );
document.write( "6×6 = 36 and the sum of its digits is 3+6 or 9.\r\n" );
document.write( "\r\n" );
document.write( "What do you know?  That must be the answer, 6.\r\n" );
document.write( "\r\n" );
document.write( "Now was that really too difficult for you to answer all by yourself?\r\n" );
document.write( "\r\n" );
document.write( "Edwin
\n" ); document.write( "
\n" );