=[(x+1)(x+7)][(x+3)(x+5)]-12=(x²+8x+7)(x²+8x+15)-12=(x²+8x)²+22(x²+8x)+105-12=(x²+8x)²+22(x²+8x)+93=【x²+8x+11】²-28=(x²+8x+11+2√7)(x²+8x+1...