The sum of the digits of a two-digit number is 12. the number formed by interchanging the digits is 54 more than the original number. what is the original number? 39 48 57

Let's call the digits of the number ab a and b. Then the information in the question can be expressed as

a+b=12 => b=12-a
a*10+b + 54 = b*10+a => 9a + 54 = 9b

9a + 54 = 9(12-a) => 18a = 54 => a=3

b=12-a; b=9

39 swapped gives 93, 39+54=93

Idon’t know actually i’m in 5th grade and don’t know