分解因式难度中等的一些题目

我发好了

1.4x^2-14x+6 =(x-3)(4x-2)十字相乘法

3.xy(xy+1)+(xy+3)-2(x+y+1/2)-(x+y-1)^2
=xy(xy+1)+(xy+1)+2-2(x+y)-1-(x+y)²+2(x+y-1)-1
=(xy+1)²-(x+y)²-2

1.4x^2-14x+6 = 2(2x^2-7x+3) =2(x-3)(2x-1)

2.3x^2+5xy-2y^2+xz+9yz-4z^2 =(3x-y)(x+2y)

3.xy(xy+1)+(xy+3)-2(x+y+1/2)-(x+y-1)^2
= (xy)^2+xy +xy +3 -2x-2y-1-x^2-y^2-2xy+2x+2y-1
=（xy）^2 -x^2-y^2 +1 =x^2(y^2-1)-(y^2-1) = (x+1)（x-1）(y+1)(y-1)

4.(x^2+5x+6)(x^2+7x+6)-3x^2
=

5.(x^2+3x+2)(4x^2+8x+3)-90

好麻烦的题目。。。。

1.2(x-3)(2x-1)
2.(3x-y+4z)(x+2y-z)
3.化简得：x²y²-x²-y²+1=(x²-1)（y²-1）=(x+1)(x-1)(y+1)(y-1)

1.2(x-3)(2x-1)
2.(x+2y-z)(3x-y+4z)
3.(x+1)(y+1)(x-1)(y-1)
4.(x^2+6x+8)(x^2+4x+6)
5.(x-1)(4x^3+24x^2+59x+84)

1.4x^2-14x+6
=2(2x^2-7x+3)
=2(2x-1)(x-3)

2.3x^2+5xy-2y^2+xz+9yz-4z^2
=(3x-y)(x+2y)+(xz+9yz)-4z^2