[ x^4 - x^3 + 7*x^2 + 43*x + 47, \ x^4 - x^3 - 2*x^2 + 32*x - 40, \ x^4 - 17*x^2 + 324, \ x^4 - x^3 - 258*x^2 - 752*x + 577 ]