The original number is 38
Step-by-step explanation:
Let the sum of the digits of a 2 digit number is 11.
If the digits are reversed, the number formed is 45 more than the original number.
Let x and y be the two numbers and 

Let the original number be 

Let the reversed number be 

We need to determine the original number.
Original number:
We need to determine the original number 

Thus, we have,
 -----(1)
 --------(2)
Solving the equation (2), we get,

 

 

 
 --------(3)
Adding the equations (1) and (3), we get,

 

Thus, the value of x is 3
Substituting 
 in equation (1), we get,

 

Thus, the value of y is 8.
The equation of the original number is 

Substituting the value of x and y, we get,
Original number = 

Thus, the original number is 38.