已知a的平方+3a+1=0,求代数式2a的四次方+6a的立方-4a+a分之2-2的值

∵a的平方+3a+1=0
∴a²+3a=-1 a+3=-1/a a+1/a=-3
2a的四次方+6a的立方-4a+a分之2-2
=2a²(a²+3a)-6a+2a+2/a-2
=-2(a²-3a)+2a+2/a-2
=2+2a+2/a-2
=2(a+1/a)
=2x(-3)
=-6