因式分解。急求。

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3.D
4.B
5.C
7.(2X+3)(2X-3)
8.a(a+1)(a-1)
9.(x-y)(m+n)
10.3m(2x-y+n)(2x-y-n)
11.2x(x-1)^2
12.3(a+1)^2
13.12
14.15

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3.D
4.B
5.C
7.(2x+3)(2x-3)
8.a(a+1)(a-1)
9.(m+n)(x-y)
10.3m(2x-y+n)(2x-y-n)
11.2x(x-1)^2
12.3(a+1)^2

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