Answer:
[tex]\huge \boxed{\mathrm{CH_4+ 2O_2 \Rightarrow CO_2 +2 H_2O}}[/tex]
[tex]\rule[225]{225}{2}[/tex]
Explanation:
[tex]\sf CH_4+ O_2 \Rightarrow CO_2 + H_2O[/tex]
Balancing the Hydrogen atoms on the right side,
[tex]\sf CH_4+ O_2 \Rightarrow CO_2 +2 H_2O[/tex]
Balancing the Oxygen atoms on the left side,
[tex]\sf CH_4+ 2O_2 \Rightarrow CO_2 +2 H_2O[/tex]
In a balanced equation, the product side and the reactant side must have the same mass of matter, since matter cannot be destroyed or created according to the law.
[tex]\rule[225]{225}{2}[/tex]