因式分解3x^+4xy-y^解答如下：3x²+4xy-y²=7x²-﹙4x²-4xy+y²﹚=﹙√7x﹚²-﹙2x-y﹚²=[√7x+﹙2x-y﹚][√7x-﹙2x-y﹚]=﹙√7x+2x-y﹚﹙√7x-2x+y﹚=[﹙√7+2﹚x-y][﹙√7-2﹚x+y]...