efectuati:a) (x-2)(x²+x+1)-(x+2)(x²-2x+4)b) (x+3)(x²-3x+9)-(x+1)(x²-x+1)c) (x-3)(x²+3x+9)-(x-4)+(x²+4x+16)d) (x+5)(x²-5x+25)-(x+6)(x²-6x+36)