申炫城
幼苗
共回答了18个问题采纳率:94.4% 举报
1. 3(x-y)^2+4(x-y)-4
=[3(x-y)-2]*[(x-y)+2]
=(3x-3y-2)(x-y+2)
.
2. 2(2m-n)^2 +7(2m-n)-15
=[2(2m-n)-3]*[(2m-n)+5]
=(4m-2n-3)(2m-n+5)
.
3. x^2-2xy+10x-10y+25
=x²+10x+25 - 2xy-10y
=(x+5)²-2y(x+5)
=(x+5)(x+5-2y)
=(x+5)(x-2y+5)
.
4. (x-y)^2-2x+2y
=(x-y)²-2(x-y)
=(x-y)(x-y-2)
1年前
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