Zn(s) + Cu(NO3)2(aq) → Zn2+(aq) + Cu(s) + NO3–(aq)
Zn(s) → Zn2+(aq) + 2 e–
Cu(NO3)2(aq) + 2 e– → Cu(s) + 2 NO3–(aq)
Zn(s) + Cu(NO3)2(aq) → Zn2+(aq) + Cu(s) + 2 NO3–(aq)
(this one could be done by inspection easily)