2. 1) 3x^2 - 9x - 30 = 0
D = 81 - 4 * 3 * (-30) = 441
x1 = 9 + 21 / 6 = 5
x2 = 9 - 21 / 6 = -2
2) x^2 - x - 2 = 0
D = 1 - 4 * 1 * (-2) = 9
x1 = 1 + 3 / 2 = 2
x2 = 1 - 3 / 2 = -1
1. 3x^2 - x - 9 = 0
D = 1 - 4 * 3 * (-9) = 109
Кол-во корней - 2
11x^2 + x + 9 = 0
D = 1 - 4 * 11 * 9 = -395
Кол-во корней - 0
49x^2 - 28x + 4 = 0
D = 784 - 4 * 49 * 4 = 0
Кол-во корней - 1