Hey there!
NaBr + Cl₂ → NaCl + Br₂
First balance Na.
One on the left, one on the right: already balanced.
Next balance Br.
One on the left, two on the right. Add a coefficient of 2 in front of NaBr.
2NaBr + Cl₂ → NaCl + Br₂
Lastly balance Cl.
Two on the left, one on the right. Add a coefficient of 2 in front of NaCl.
2NaBr + Cl₂ → 2NaCl + Br₂
This is our final balanced equation.
Hope this helps!