document.write( "Question 1207727: The sum of the digits of a two-digit number is 5. If 9 is subtracted from the number, the digits will be interchanged. Find the number. \r
\n" ); document.write( "\n" ); document.write( "I had completed this much:\r
\n" ); document.write( "\n" ); document.write( "assume ab is a number, a being in the 10's place and b being in the units place.
\n" ); document.write( "ab=10a+b
\n" ); document.write( "a+b=5
\n" ); document.write( "9-(10a+b)=(10b+a)\r
\n" ); document.write( "\n" ); document.write( "But I am now confused on to what to substitute and how to do it. \n" ); document.write( "

Algebra.Com's Answer #845748 by ikleyn(52814) $\"\"$ $\"About$

You can put this solution on YOUR website!
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document.write( "The equation in your post is INCORRECT.\r\n" );
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document.write( "The correct equation is\r\n" );
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document.write( "    (10a+b) - 9 = 10b + a    (literal translation from English to Math).\r\n" );
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document.write( "It gives\r\n" );
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document.write( "    10a - a - 9 = 10b - b\r\n" );
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document.write( "       9a   - 9 = 9b\r\n" );
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document.write( "From a+b = 5, express a = 5-b  and substitute it into the last equation\r\n" );
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document.write( "    9(5-b) - 9 = 9b\r\n" );
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document.write( "    45 - 9b - 9 = 9b\r\n" );
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document.write( "    45 - 9 = 9b + 9b\r\n" );
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document.write( "       36  =    18b\r\n" );
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document.write( "        b  =  36/18 = 2.\r\n" );
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document.write( "So, b= 2;  a = 5-b = 5-2 = 3.\r\n" );
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document.write( "ANSWER.  The number is  10*3+2 = 32.\r\n" );
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\n" ); document.write( "\n" ); document.write( "Solved.\r
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\n" ); document.write( "\n" ); document.write( "To see many other similar solved problems on reversing digits, look into the lesson\r
\n" ); document.write( "\n" ); document.write( " - Word problems on reversing digits of numbers\r
\n" ); document.write( "\n" ); document.write( "in this site.\r
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\n" ); document.write( "\n" ); document.write( "Learn the subject from there.\r
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