39952

AB
+AB
=BC

Start B with 1, but B can't be 1 because if B+B=2, then A+A has to equal 2, the only way A+A could equal 2 is if A=1. It can't equal 1 though as B already equals 1. They have to be different . B has to be under 5 as there would be an extra number to add to A, which wouldn't make the answer possible as A+A is the same number, they can't be two different numbers.

Solutions:
12
+12
= 24.

24
+24
=48