3(9-6x^2+x^4)-(9x^2+27-3x^4+x^6+3x^4)-3(x^4-x^2)=27-18x^2+3x^4-9x^2-27+3x^4-x^6-3x^4-3x^4+3x^2= -x^6-24x^2+54
3(9-6x^2+x^4)-(9x^2+27-3x^4+x^6+3x^4)-3(x^4-x^2)=27-18x^2+3x^4-9x^2-27+3x^4-x^6-3x^4-3x^4+3x^2= -x^6-24x^2+54