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

1)7x(×^2-4)=0x1=0x^2=4x2=2x2=-22)x(81x^2+36x+4)=0x=081x^2+36x+4=0d=1296-1296=0x1/2=-b/2*a=-36/162=0,23)