6x^2-13x+6 2x^2-8xy+8y^2-11x+22y+15 因式分解

问题描述:

6x^2-13x+6 2x^2-8xy+8y^2-11x+22y+15 因式分解

十字相乘
1原式=(2x-3)^2
2原式=(x-2y-3)(2x-4y-5)

6x²-13x+6=(2x-3)(3x-22x²-8xy+8y²-11x+22y+15=2(x²-4xy+4y²)-11(x-2y)+15=2(x-2y)²-11(x-2y)+15 相当于2a²-11a+15=[2(x-2y)-5][(x-2y)-3]=(2x-4y-5)(x-2y-3)