Question 339427
If the tens digit x and the unit digit y of a positive integer n are reversed, the resulting integer 9 is more than n, what is y in terms of x?
<pre><b>
The given positive integer n = 10x + y

The resulting positive integer when the integers are reversed is 10y + x

(10y + x) = (10x + y) + 9

  10y + x = 10x + y + 9

Add -y - x to both sides

   9y = 9x + 9

    y = x + 1

Edwin</pre></b>