1) х^2 - 34х + 289 = 0
D = 1156-1156 = 0, x = -b/2a = 34/2 = 17
Ответ: 17
2) 2y^2 - 5y - 3 = 0
D = 25+24 = 49 = 7^2
x1 = 5-7/4 = -0,5
x2 = 5+7/4 = 3
Ответ: -0,5; 3
3) a^2 + 9a + 4 = 0
D = 81-16 = 65 = √65
х1 = -9-√65/2
х2 = -9+√65/2
Ответ: -9-√65/2; -9+√65/2