document.write( "Question 259429: the sum of the digits of a two digit number is 15. if the digits are interchange the result exceeds the original number by 9. find the number. \n" ); document.write( "
Algebra.Com's Answer #190985 by palanisamy(496)\"\" \"About 
You can put this solution on YOUR website!
Let the number be xy.
\n" ); document.write( "Given,the sum of the digits of a two digit number is 15.
\n" ); document.write( " x+y = 15 ...(1)
\n" ); document.write( "Also, if the digits are interchanged the result exceeds the original number by 9.
\n" ); document.write( " 10y+x=10x+y+9
\n" ); document.write( " 10y+x-10x-y=9
\n" ); document.write( " 9y-9x=9
\n" ); document.write( " y-x=1 ...(2)
\n" ); document.write( "(1)+(2) => 2y = 16
\n" ); document.write( " y = 16/2 = 8
\n" ); document.write( "(1) => x+8=15
\n" ); document.write( " x=15-8=7
\n" ); document.write( "Therefore the given number is 78
\n" ); document.write( "
\n" );