Х⁴+2х²-6х²-12=х⁴-4х²+4-х -4х²-12+4х²-4+х=0 -16+х=0 х=16
X⁴+2x²-6x²-12=x⁴-4x²+4-x x⁴-x⁴-4x²+4x²-12-4=-x x=16