Question 1207727
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<pre>

The equation in your post is INCORRECT.


The correct equation is

    (10a+b) - 9 = 10b + a    (literal translation from English to Math).


It gives

    10a - a - 9 = 10b - b

       9a   - 9 = 9b


From a+b = 5, express a = 5-b  and substitute it into the last equation

    9(5-b) - 9 = 9b

    45 - 9b - 9 = 9b

    45 - 9 = 9b + 9b

       36  =    18b

        b  =  36/18 = 2.


So, b= 2;  a = 5-b = 5-2 = 3.


<U>ANSWER</U>.  The number is  10*3+2 = 32.
</pre>

Solved.


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&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF=http://www.algebra.com/algebra/homework/word/misc/Word-problems-on-interchanging-digits-of-numbers.lesson>Word problems on reversing digits of numbers</A>

in this site.


Learn the subject from there.