\[\boxed{\text{516\ (516).\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
\[1)\ (x - 17)(x + 17) =\]
\[= x^{2} + 6x - 49\]
\[x^{2} - 289 = x^{2} + 6x - 49\]
\[6x = - 240\]
\[\ x = - 40\]
\[Ответ:\ x = - 40.\]
\[1,44x^{2} - 16 - 1,69x^{2} + 4 =\]
\[= 4x - 0,25x^{2}\]
\[4x = - 12\]
\[\ \ x = - 3\]
\[Ответ:\ x = - 3.\]