这些题都是十字分解法啊,
(1) 2x²-7x+3=﹙2x-1﹚﹙x-3﹚
(2)3x²-13x-10=﹙x-5﹚﹙3x+2﹚
(3)6x²-7x-5=﹙3x-5﹚﹙2x+1﹚
(4)x²-3xy+2y²=﹙x-y﹚﹙x-2y﹚
(5)5x²+6xy-8y²=﹙5x-4y﹚﹙x+2y﹚
(6)3a²x²-15a²xy-42a²y²=3a²﹙x²-5xy-14y²﹚=3a²﹙x+2y﹚﹙x-7y﹚
﹙1﹚=﹙2X-1﹚﹙X-3﹚
﹙2﹚=﹙3X+2﹚﹙X-5﹚
﹙3﹚=﹙3X-5﹚﹙2X+1﹚
﹙4﹚=﹙X-Y﹚﹙X-2Y﹚
﹙5﹚=﹙5X-4﹚﹙X+2﹚
﹙6﹚=3a²﹙x+2y﹚﹙1-7y﹚