in a 2 digit number sum of two digit is 7 of the difference of two digit number and number obtained by reversing the degit is 9 find the numbers

2 answers

0, 7
1, 6
2, 5
3, 4

Which of those combinations meets the second criterion?
Let m be the ten digit, and n be the ones. Then:
m+n=7
(10m+n)-(10n+m)=9
Then:
10m-10n+n-m=9
Solve for m and n
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