Răspuns :
(3x-1)²-2 (x+2)²+ 3(1-x)(1+x)=
= (3x)²+1-6x-2(x²+4+4x)+3(1-x²)
=9x²+1-6x-2x²-8-8x+3-3x²
=(9x²-2x²-3x²)+(1-8+3)-6x-8x
=3x²-4-14x
= (3x)²+1-6x-2(x²+4+4x)+3(1-x²)
=9x²+1-6x-2x²-8-8x+3-3x²
=(9x²-2x²-3x²)+(1-8+3)-6x-8x
=3x²-4-14x
=9x²-6x+1-2(x²+4x+4)+3(1+x-x-x²)
=9x²-6x+1-2x²-8x-8+3-3x²
=4x²-14x-4
=9x²-6x+1-2x²-8x-8+3-3x²
=4x²-14x-4