3*x^2 - 10*x + 3 = 0
d = 100 - 3 * 3 * 4 = 64
х1 = (10 - 8) / 6 = 1/3
x2 = (10 + 8) / 6 = 3
3*x^2 - 10*x + 3 = 3(x - 1/3)(x - 3)
x ^ 2 - 9 = (x - 3)(x + 3)
Сокращаем на х - 3, получаем (3x - 1)/(x + 3)
2) 5 * x ^ 2 + x - 4 = 0
D = 1 + 4 * 4 * 5 = 81
x1 = (-1 + 9)/10 = 4/5 = 0.8
x2 = (-1 - 9)/10 = -1
5 * x ^ 2 + x - 4 = 5 * (x - 0.8)*(x + 1)
x^2 + x = x*(x+1)
