x^3 - 3x^2 - 4x + 12 = 0
x^3 - 4x - (3x^2 - 12) = 0
x(x^2 - 4) - 3(x^2 - 4) = 0
(x^2 - 4)(x - 3) = 0
(x - 2)*(x + 2)*(x - 3) = 0
x1 = 2,
x2 = -2,
x3 = 3
2 3х
---- = --------
х-5 х+3
2 3х
---- - -------
х-5 х+3
2х+6-3х²+15х=0
3х²-17х-6=0
д=361=19
х1=6
х2=1
- -----
3
(a+b)(x+y)=ax+by расскрываем скобку