The first equation "6H2O + 6O2 + light → C6H12O6 + 6CO2" does not correctly model photosynthesis.
In photosynthesis, the process converts carbon dioxide (CO2) and water (H2O) into glucose (C6H12O6) and oxygen (O2) in the presence of light. The correct reaction is typically represented as:
\[ 6CO2 + 6H2O + light \rightarrow C6H12O6 + 6O2 \]
The other equations (the second, third, and fourth) correctly represent the process of photosynthesis in various forms.