X^4 + 4 = 0
x^4 = -4
1)x = -(-1)^(1/4)*sqrt(2)
2)x = (-1)^(1/4)*sqrt(2)
3)x = -(-1)^(3/4)*sqrt(2)
4)x = (-1)^(3/4)*sqrt(2)
Ответ: x= -1-i, x = -1+i, x=1-i, x=1+i.
x^3 - 8 = 0
x^3 = 8
1)x = 2
2)x = -2 (-1)^(1/3)
3)x = 2 (-1)^(2/3)
Ответ: x= -1 - i sqrt(3), x = -1 + i sqrt(3), x=2.