Question

1. 18у^3-36y^2=0
2. х^2+0,9х=0
3. (x^2-10)^2-3(x^2-10)+4=0
4. (x^2+x+6)(x^2+x-4)=144
5. x^4-10x^2+9=0
6. x^4+6x^2-27=0
7. x^6-x^4+5x^2-5=0
ПОМОГИТЕ