1:分解因式4(x+2y)²-25(x-y)²=...2:把9(x-y)+12(

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(x+2y)²-25(x-y)²
=(x+2y+5x-5y)(x+2y-5x+5y)
=(6x-3y)(7y-4x)
=3（2x-y)(7y-4x)
9(x-y)²+12(x²-y²)+4(x+y)²
=(3x-3y+2x+2y)^2
=(5x-y)^2
(x+y)^m+1-(x+y)^m-1
=(x+y)^m-1(x+y+1)(x+y-1)
-3y^4+10y²+8
=-(3y^2+2)(y^2-4)
=-(3y^2+2)(y+2)(y-2)
======以下答案可供参考======
供参考答案1:
4(x+2y)²-25(x-y)²
=(6x-3y)(7y-4x)
=3（2x-y)(7y-4x)
9(x-y)^2+12(x²-y²)+4(x+y)² (题目有问题？)
=(3x-3y+2x+2y)^2
=(5x-y)^2
(x+y)^m+1-(x+y)^m-1
=[(x+y)^m-1][(x+y)^2]-(x+y)^m-1 *1
=(x+y)^m-1*[x+y+1](x+y-1)
-3y^4+10y²+8
=.....配方再分解（这题的数据，晕了~~）
供参考答案2:
（1）(x+2y)²-25(x-y)²
=(x+2y+5x-5y)(x+2y-5x+5y)
=(6x-3y)(7y-4x)
=3（2x-y)(7y-4x)
（2）9(x-y)²+12(x²-y²)+4(x+y)²
=(3x-3y+2x+2y)^2
=(5x-y)^2
（3）(x+y)^m+1-(x+y)^m-1=(x+y)^m-1(x+y+1)(x+y-1)
（4）-3y^4+10y²+8=-(3y^2+2)(y^2-4)
=-(3y^2+2)(y+2)(y-2)
供参考答案3:第二个（2-y）*（2+y）*（3y^2+2）供参考答案4:4(x+2y)²-25(x-y)²
=[2(x+2y)-5(x-y)][2(x+2y)+5(x-y)]=(2x+4y-5x+5y)(2x+4y+5x-5y)=9y-3x)(7x-y)9(x-y)²+12(x²-y²)+4(x+y)²
=9(x-y)²+12(x-y)(x+y)+4(x+y)²=[3(x-y)+2(x+y)]²=(3x-3y+2x+2y)²=(5x-y)²(x+y)^m+1-(x+y)^m-1
=(x+y)^m-1[(x+y)²-1]=(x+y)^m-1(x+y+1)(x+y-1)
-3y^4+10y²+8
=-(3y^4-10y²-8)=-(3y²+2)(y²-4)=-(3y²+2)(y-2)(y+2)