Resumen

\[x^2 = 25\]
\[x=\boxed{-5, 5}\]

\[x^2 = 64\]
\[x=\boxed{-8, 8}\]

\[x^2 = \frac{16}{25}\]
\[x=\boxed{\frac{-4}{5}, \frac{4}{5}}\]

\[( x - 9 ) ( x - 5 ) = 0\]
\[x=\boxed{9, 5}\]

\[( x + 9 ) ( x + 1 ) = 0\]
\[x=\boxed{-9, -1}\]

\[( x + 7 ) ( x - 5 ) = 0\]
\[x=\boxed{-7, 5}\]