Use the following steps to balance the redox reaction using half-reactions.
Zn(s) + Fe3+ → Zn2+ + Fe(s) (unbalanced)

a. Write balanced oxidation and reduction half-reactions. Indicate which is the
oxidation reaction and which is the reduction reaction.

b. Balance the charge in the two half reactions by multiplying the half-reactions by correct multiplication factors.

c. Add the equations and simplify to get the balanced equation.