document.write( "Question 1080520: The sum of a two digit number and the number obtained by reversing its digits is a square number. How many such numbers are there? \n" ); document.write( "
Algebra.Com's Answer #694654 by KMST(5328)\"\" \"About 
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\n" ); document.write( "Let \"a\" be the first digit, and let \"b\" be the second digit.
\n" ); document.write( "The value of the number is \"10a%2Bb\" .
\n" ); document.write( "The value of the number obtained by reversing its digits is \"10b%2Ba\" .
\n" ); document.write( "Their sum is
\n" ); document.write( "\"10a%2Bb%2B10b%2Ba=11a%2B11b=11%28a%2Bb%29\" .
\n" ); document.write( "For that sum to be the square of an integer, it must be true that
\n" ); document.write( "\"a%2Bb=11\" .
\n" ); document.write( "There are \"4\" possible pastors of digits adding to \"11\" :
\n" ); document.write( "\"2%2B9=11\" ,
\n" ); document.write( "\"3%2B8=11\" ,
\n" ); document.write( "\"4%2B7=11\" , and
\n" ); document.write( "\"5%2B6=11\" .s
\n" ); document.write( "Since we can make two 2-digit number out of each paiR
\n" ); document.write( "by changing the other of the digits,
\n" ); document.write( "there are \"2%2A4=8\" numbers that could be
\n" ); document.write( "the original 2-digit number in the problem.
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