giải phương trình
\(-6\left(-x^2-x+1\right)^4+x^2\left(-x^2-x+1\right)^2+5x^4=0\)
b) \(x^4+9=5x\left(x^2-3\right)\)
c) \(x^4+\left(x+1\right)\left(5x^2-6x-6\right)=0\)
d)\(\left(x^2+1\right)^2+\left(x+1\right)\left(3x^2+2x-2\right)=0\)
e) \(x^2\left(x-1\right)^2+x\left(x^2-1\right)=2\left(x+1\right)^2\)