I would say my friend is correct. I think this because when doing function tables, i would often say x2, x5, etc. This would mean that it would be X x 2, and X x 5. If you replace the "x" and turn it into 8, than I would think it would mean the same thing. So, yes. My friend is correct.
I'm not sure if this was what you were looking for, but I hope this helps somehow!
