The sum of the digits of a 2-digit number?

Q1:
Tens digit:
9 - x = x - 5
2x = 14
x = 7

Unit digit:
= 9 - 7
= 2

Answer: 72 is the number.

Q2:
7 - x = x + 3
2x = 4
x = 2

= 7 - 2
= 5

Answer: 25 is the number.