FeO = Iron$II$ oxide
FeSO4 = Iron$II$ sulfate
Fe$OH$3 = Iron$III$ hydroxide
FeO = Iron$II$ oxide
Fe = Iron
FeCl = Iron$III$ chloride
H2O = Water
O3 = Ozone
CO3 = Carbonate
CuCO3 = Copper$II$ carbonate
Ca$NO3$2 = Calcium nitrate

Therefore, the complete equation is:
Iron$II$ oxide = Iron$II$ sulfate = Iron$III$ hydroxide = Iron$II$ oxide = Iron = Iron$III$ chloride = Water = Ozone = Carbonate = Copper$II$ carbonate = Calcium nitrate