write the empirical formula for each of the following molecular formulae"

Question

a)P4O10
b)C2H6

Confused as to what the diff.is b/w empirical and formula...have no idea how to answer these b/c they look like empirical formulas to me

Answer 1

empirical is lowest whole ratio
P2O5
formula reflects how it is combined
P4O10

Answer 2

THANKS FOR ALL YOUR HELP TODAY.