2. Reaction in response to a change in the environment

Which is the correct formula for photosynthesis

Construct at least two possible hypotheses for the student’s experiment.

Ihave no idea how to solve these. plus there's another question that is 2) a 10 kilogram meteorite is collected in space and brought back to earth. it is composed of 1.25 kg of uranium-238 and 8.75 kg of lead-206. how many u-238 half lives have passed? what is the approximate age of the meteorite?