Răspuns :
x⁴+x²+1=(x²+x+1)(x²-x+1)
(x²+x+1)(x²-x+1)=x⁴-x³+x²+x³-x²+x+x²-x+1=grupam termeni=
=x⁴-x³+x³+x²-x²+x²+x-x+1=x⁴+x²+1
(x²+x+1)(x²-x+1)=x⁴-x³+x²+x³-x²+x+x²-x+1=grupam termeni=
=x⁴-x³+x³+x²-x²+x²+x-x+1=x⁴+x²+1