(x1-x2)^2=(x1+x2)^2-4x1x2=(4/3)^2-4(-2/3)=40/9
1)a = 2
Решений нет
2)a = 3
x = x-1
0≠-1
3)a€(-∞;2)U(2;3)U(3;+∞)