The reaction you're describing is the combustion of methane, which is a reaction with oxygen. Here's how it would be represented in a formula equation:

CH₄ + 2O₂ → CO₂ + 2H₂O

Explanation:

* CH₄ represents methane (one carbon atom and four hydrogen atoms).

* O₂ represents oxygen gas (two oxygen atoms bonded together).

* CO₂ represents carbon dioxide (one carbon atom and two oxygen atoms).

* H₂O represents water (two hydrogen atoms and one oxygen atom).

The coefficients (numbers in front of the molecules) balance the equation:

* 1 molecule of methane reacts with 2 molecules of oxygen to produce 1 molecule of carbon dioxide and 2 molecules of water.

This balanced equation ensures that the number of atoms of each element is the same on both sides of the equation, following the law of conservation of mass.