-(x²-5)²-8(x²-5)-16=-[(x²-5)²+2×(x²-5)×4+4²]=-[(x²-5)+4]²=-(x²-1)²=-[(x+1)(x-1)]²=-(x+1)²(x-1)²请点击下面的【选为满意回答】按钮....