0xBED is an hexadecimal representation.
Transforming to decimal first:
B => 11
E => 14
D => 13
[tex]11\times16^2+14\times16+13=3053[/tex]
Now by successive devisions, we get the base three:
[tex]3053=2+2\times3^3+3^4+3^6+3^7[/tex]
And the resulting base three expression:
[tex]11012002_{3}[/tex]
