Answer:
3CH₄ + 3N₂Cl₄ → 3CCl₄ + 3N₂ + 6H₂
Explanation:
  Carbon_black sphere
  Nitrogen_blue sphere
  Chlorine_green sphere
  Hydrogen_white sphere
Reactants:
Three molecules that contain one black sphere and four white spheres
3CHâ‚„ Â Â Â Â Â
Three molecules that contain two blue spheres and four green spheres:
3Nâ‚‚Clâ‚„
Products:
Three molecules that contain one black sphere and four green spheres:
3CClâ‚„
Three molecules that contain two blue spheres:
3Nâ‚‚
Six molecules that contain two white spheres
6Hâ‚‚
The reaction proper:
3CH₄ + 3N₂Cl₄ → 3CCl₄ + 3N₂ + 6H₂
Sidenote: I hope this answer helps!