(3x-1)²-2(x+2)²+3(1-x)(1+x)=
=9x²-6x+1-2(x²+4x+4)+3-3x²=
=9x²-6x+1-2x²-8x-8+3-3x²=
=4x²-14x+4=
=2(2x²-7x+2)
Aratati ca : (x-2)(x+2)(x²+4)(x⁴+16 )(x⁸ +256) = x¹⁶ -2¹⁶
(x-2)(x+2)(x²+4)(x⁴+16 )(x⁸ +256) = (x²-4)(x²+4)(x⁴+16 )(x⁸ +256) =
= (x⁴-16)(x⁴+16 )(x⁸ +256) = (x⁸-2⁸)(x⁸ +2⁸) =x¹⁶-2¹⁶