Answer:
The number is 53.
Explanation:
If the digits are x and y where x is the first digit then we have the equations:
x + y = 8.........(1)
10x + y - (10y + x) = 18
9x - 9y = 18
Dividing through by 9:
x - y = 2..........(2)
Adding (1) and (2):
2x = 10
x = 5
and y = 8 - 5 = 3.