метот группировки.....
y³+3y²-y-3=0
(y³+3y²)-(y+3)=0
y²(y+3)-(y+3)=0
(y+3)(y²-1)=0
(y+3)(y-1)(y+1)=0
y1 = -3
y2 = 1
y3 = -1
метот группировки.....
y³+3y²-y-3=0
(y³+3y²)-(y+3)=0
(y³+3y²)-(y+3)=0
y²(y+3)-(y+3)=0
(y+3)(y²-1)=0
(y+3)(y-1)(y+1)=0
y1 = -3
y2 = 1
y3 = -1