Use E°(Ag⁺/Ag) = +0.80 V and E°(Cu²⁺/Cu) = +0.34 V…

Step 1. Silver in $\text{Cu}^{2+}$. Copper ions would be reduced and silver oxidised: $E^\circ = 0.34 - 0.80 = -0.46\ \text{V}$. Negative: no reaction.

Step 2. Copper in $\text{Ag}^+$. Silver ions are reduced and copper oxidised: $E^\circ = 0.80 - 0.34 = +0.46\ \text{V}$. Positive: the reaction happens.