2道因式分解、急~1. (x+1)²-9(x-1)²2. 4a²b²-(a²+b²-c²)²

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2道因式分解、急~1. (x+1)²-9(x-1)²2. 4a²b²-(a²+b²-c²)²
2道因式分解、急~
1. (x+1)²-9(x-1)²
2. 4a²b²-(a²+b²-c²)²

2道因式分解、急~1. (x+1)²-9(x-1)²2. 4a²b²-(a²+b²-c²)²
1.(x+1)²-9(x-1)²
=[(x+1)+3(x-1)][(x+1)-3(x-1)]
=(4x-2)(-2x+4)
=-4(x-2)(x-2)
=-4(x-2)²
2.4a²b²-(a²+b²-c²)²
=[2ab+(a²+b²-c²)][2ab-(a²+b²-c²)]
=[(a+b)²-c²][c²-(a-b)²]
=(a+b+c)(a+b-c)(c+a-b)(c-a+b)