<h2>Explanation:</h2><h2></h2>
Here we need to set a system of two linear equations in two variables. So:
- <em>The sum of digits in a two digit number formed by two digits from 1 to 9 is 8:</em>
Let be those digits, then:
- <em>If 9 is added to a number then both the digits become equal. find the number:</em>
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But from eq 1:
Substituting y into the expression 1:
The x-value will be found by hit and trial, so:
- Let x = 1:
We have to reject this solution because digits are different.
- Let x = 2:
We have to reject this solution because digits are different.
- Let x = 3:
<em>Then this is a two digit number formed by two equal digits. </em>
Finally, the number is:
44
