When you reverse the digits in a certain two digit number you decrease it's value by 36. Find the number if the sum of its digits is 10

The number is 73.

Step-by-step explanation:

I. 10b + a = 10a + b - 36

II. a + b = 10 - -> b = 10 - a

II in I

10b + a = 10a + b - 36

9b = 9a - 36

9 (10 - a) = 9a - 36

90 - 9a = 9a - 36

126 = 18a

a = 7

b = 10 - 7 = 3