Are my oxidation, reduction and balanced equation correct?

[Moribundus]

I just want to know if the following makes any sense. If it doesn, what am I doing wrong?

Oxidation: Mg(s) → Mg2+(aq) +*2e

Reduction: Cu2+(aq) + 2e → Cu(s)

Balanced equation: 2 Cu3+(aq) + Mg(s) → 2 Cu(s) + 2 Mg2+(aq)

Thanks guys in advance!