\[\boxed{\text{641\ (641).\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
\[1)\ x² + 12x + 36 = 0\]
\[(x + 6)^{2} = 0\]
\[x + 6 = 0\]
\[x = - 6\]
\[Ответ:\ x = - 6.\]
\[2)\ 25x² - 30x + 9 = 0\]
\[(5x - 3)^{2} = 0\]
\[5x - 3 = 0\]
\[x = \frac{3}{5}\]
\[Ответ:x = \frac{3}{5}.\]
\[\boxed{\text{641.\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
\[= 5^{24} - 5^{24} + 256 = 256\]