Ineed ! what is a variable that meteorologist track to make weather forecast? the answers are either: air pressure or barometer!

A barometer is a tool, not a variable. A barometer measures barometric or air pressure, which is a variable that meteorologists use to predict the weather.

I agree a barometer is a tool used to predict weather while a variable is something to take into account when meteorologists are taking data and could effect there data so air pressure is the variable

The correct answer is a

1. and 2. question: in which equation? or i don't understand you, 3. a), 4. c), 5. c), 6. b), 7. d), 8. d) if small number is underlined(behind symbol) , b) if big number is underlined(in front of symbol)9. what is underlined there? 10. c)