The transformed functions are:
- \( f_1(x) = -\sqrt{x} - 8 \)
- \( g_1(x) = -\sqrt{-x} - 16 \)
- \( f_2(x) = 8 - \sqrt{x} \)
- \( g_2(x) = -\sqrt{-x} \)
- \( f_3(x) = \sqrt{-x} + 8 \)
- \( g_3(x) = \sqrt{x} + 16 \)
Thus, the final answers are:
\[
\boxed{f_1(x) = -\sqrt{x} - 8, \quad g_1(x) = -\sqrt{-x} - 16}
\]
\[
\boxed{f_2(x) = 8 - \sqrt{x}, \quad g_2(x) = -\sqrt{-x}}
\]
\[
\boxed{f_3(x) = \sqrt{-x} + 8, \quad g_3(x) = \sqrt{x} + 16}
\]