Let \[f(x) =
\begin{cases}
3x + 5 &\text{if }x<-3, \\
7-4x&\text{if }x\ge -3.
\end{cases}
\]Find $f(-10)$.
Because $-10<-3$, we use the first case to determine that $f(-10) = 3(-10) + 5 = \boxed{-25}$.