Solve for $u$ in terms of $s, t$, and $v$.
\[
\begin{array}{l}
v=u-s-t \\
u=
\end{array}
\]
Final Answer: \(\boxed{u = s + t + v}\)
Step 1 :Add s and t to both sides of the equation: \(v = u - s - t\)
Step 2 :Final Answer: \(\boxed{u = s + t + v}\)