document.write( "Question 75181: Find digits a and b such that the number 34a47b5893 is divisible by 99. \n" ); document.write( "
Algebra.Com's Answer #54005 by nilan(17)\"\" \"About 
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Suppose 34a47b5893 is divisible by 99
\n" ); document.write( "Then obviously it is divisible by 9
\n" ); document.write( "If a number is divisible by 9 the sum of all the digits should divisible by 9 (this can be easily proved)\r
\n" ); document.write( "\n" ); document.write( "For example let the number abcd divisible by 9 then
\n" ); document.write( "\"10%5E3a%2B10%5E2b%2B10c%2Bd+=+9k\" where k is positive integer
\n" ); document.write( "Then \"1000a%2B100b%2B10c%2Bd+=+9k\"
\n" ); document.write( "\"%28999a%2Ba%29%2B%2899b%2Bb%29%2B%289c%2Bc%29%2Bd=9k\"
\n" ); document.write( "\"a%2Bb%2Bc%2Bd+=+9k-%28999a%2B99b%2B9c%29\"\r
\n" ); document.write( "\n" ); document.write( "\"a%2Bb%2Bc%2Bd+=+9%28k-111a%2B11b%2Bc%29=9K\"
\n" ); document.write( "then a+b+d+c is divisible by 9
\n" ); document.write( "This can be proved for any number (can be given a general proof. Try it)\r
\n" ); document.write( "\n" ); document.write( "Again to the problem
\n" ); document.write( "Then the sum of 34a47b5893 is divisible by 9\r
\n" ); document.write( "\n" ); document.write( "Then 3+4+a+4+7+b+5+8+9+3 is divisible by 9
\n" ); document.write( "Then
\n" ); document.write( "43+a+b is divisible by nine \r
\n" ); document.write( "\n" ); document.write( "Then a=0 and b=2
\n" ); document.write( "Or a=2 and b = 0
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