Consider the given circuit where V$1=8\mathrm{.}5$ V and V$2=20$ V$.$ Determine vo using the superposition principle

Find the value of Vo in mV Assume$$vo$1,$ vo$2,$ and vo$3$ are due to the $2-$A$,8\mathrm{.}5-$V$,$ and $20-$V sources, respectively.