РЕШЕНИЕ
1) 2x² + 5x - 7 - 0, D= 81, √81 = 9,
x1 = 1, x2 = - 3.5 - ОТВЕТ
2) 2x² + 3x - 5 = 0, D = 49, √49 = 7,
x1 = 1, x2 = - 2.5 - ОТВЕТ
3) 6x² + 5x + 1 = 0, D = 1
x1 = - 1/3, x2 = 1/2 = 0.5 - ОТВЕТ
4) 5x² - 17x - 12 = 0, D = 529, √529 = 23,
x1 = - 0.6 , x2 = 4 - ОТВЕТ