This question is not too difficult, but it's also not too fun. It's just pencil pushing.

Here's a tutorial for converting between various bases:

Introduction to decimal, binary, hexadecimal, octal and converting between bases

If I were you, I would read the section "Converting from binary, hexadecimal and octal to decimal". Then, convert each number, term by term, into decimal notation, add/subtract in decimal, and then reconvert your answer back into the various bases.

The point is that this is no harder, conceptually, than each of the following questions:

What is 57FF converted from hexadecimal to decimal?

What is 70 converted from hexadecimal to decimal?

What is 50 converted from octal to decimal?

...

Then, after getting each number in decimal form, it's just arithmetic to get a decimal based answer. Finally, you'll need to convert your answer back into each base.