Question

Решите уравнение
1)7x^3-28x=0
2)81x^3+36x^2+4x=0
3)x^3-2x^2-9x+18=0
4)x^3+4x^2+4x+16=0
5)3x^3-6x^2-75x+150=0
6)x^5+4x^4+4x^3-x^2-4x-4=0

Answer 1

1)7x(×^2-4)=0
x1=0
x^2=4
x2=2
x2=-2
2)x(81x^2+36x+4)=0
x=0
81x^2+36x+4=0
d=1296-1296=0
x1/2=-b/2*a=-36/162=0,2
3)