第1个回答 2011-11-11
1、 5a²-4a-5b²+4b
=5a²-5b²-4a+4b
=-5(a+b)(a-b)-4(a-b)
=(a-b)(5a+5b-4)
2、 3a-ax-3b+bx
=3a-3b-ax+bx
=3(a-b)-x(a-b)
=(a-b)(3-x)
3、 6a²-35xy+10ay-21ax
=6a²+10ay-35xy-21ax
=2a(3a+5y)-7x(3a+5y)
=(3a+5y)(2a-7x)
4、 x²+2x-y²+2y
=x²-y²+2x+2y
=(x+y)(x-y)+2(x+y)
=(x+y)(x-y+2)
5、3a²-2b+6ab-a
=3a²+6ab-a-2b
=3a(a+2b)-(a+2b)
=(a+2b)(3a-1)
6、1-x²-y²+2xy
=1-(x-y)²
=(1+x-y)(1-x+y)
第2个回答 2011-11-16
1)5a²-4a-5b²+4b
=5(a²-b²)-4(a-b)
=5(a+b)(a-b)-4(a-b)
=(a-b)(5a+5b-4)
2)3a-ax-3b+bx
=3a-3b-ax+bx
=3(a-b)-x(a-b)
=(a-b)(3-x)
3)6a²-35xy+10ay-21ax
=6a²+10ay-35xy-21ax
=2a(3a+5y)-7x(5y+3a)
=(2a-7x)(3a+5y)
4)x²+2x-y²+2y
=x²-y²+2x+2y
=(x+y)(x-y)+2(x+y)
=(x+y)(x-y+2)
5)3a²-2b+6ab-a
=3a²-a-2b+6ab
=a(3a-1)+2b(-1+3a)
=(a+2b)(3a-1)
6)1-x²-y²+2xy
=1-(x²-2xy+y²)
=1-(x-y)²
=(1+x-y)(1-x+y)
第3个回答 2011-11-11
1, 5a²-4a-5b²+4b=5(a²-b²)-4(a-b)=5(a﹢b)(a-b)-4(a-b)=(a-b)(5a﹢5b﹣4)
2、 3a-ax-3b+bx=3(a-b)-x(a-b)=(a-b)(3-x)
3、 6a²-35xy+10ay-21ax=2a(3a﹢5y)-7x(5y+3a)=(3a+5y)(2a-7x)
4、 x²+2x-y²+2y=(x+y)(x-y)+2(x+y)=(x+y)(x-y-2)
5、3a²-2b+6ab-a=3a(a+2b)-(a+2b)=(a+2b)(3a-1)
6、1-x²-y²+2xy=1-(x-y)²=(1-x+y)(1+x-y)
第4个回答 2011-11-11
1、 5a²-4a-5b²+4b
=4b-5b²-4a+5a²
2、 3a-ax-3b+bx
=3a-3b+(-a+b)x
3、 6a²-35xy+10ay-21ax
=-35xy+10ay-21ax+6a²
4、 x²+2x-y²+2y
=-y²+2y+2x+x²
5、3a²-2b+6ab-a
=-2b+6ab-a+3a²
6、1-x²-y²+2xy
=1-y²+2xy-x²
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