(3x²+2x+1)²-(2x²+3x+3)²
=(3x²+2x+1+2x²+3x+3)(3x²+2x+1-2x²-3x-3)²
=(5x²+5x+4)(x²-x-2)
=(5x²+5x+4)(x+1)(x-2)

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