Hey there!
Na + FeBr₂ → NaBr + Fe
Firstly, balance Br.
Two on the left, one on the right. Add a coefficient of 2 in front of NaBr.
Na + FeBr₂ → 2NaBr + Fe
Next, balance Na.
One on the left, two on the right. Add a coefficient of 2 in front of Na.
2Na + FeBr₂ → 2NaBr + Fe
Lastly, balance Fe.
One on the left, one on the right. Already balanced.
Our final balanced equation:
2Na + FeBr₂ → 2NaBr + Fe
Hope this helps!