(x+y）²-2（x²-y²）+（x-y）²,提取公因式

(x+y）²-2（x²-y²）+（x-y）²,提取公因式
(x+y）²-2（x²-y²）+（x-y）²,提取公因式

(x+y）²-2（x²-y²）+（x-y）²,提取公因式
(x+y）²-2（x²-y²）+（x-y）²
=(x+y）²-2(x+y）（x-y）+（x-y）²
=[(x+y）-(x-y）]²
=﹙x+y-x+y﹚²
=4y²

原式=(x+y)²-2(x+y)(x-y)+(x-y)²
=[(x+y)-(x-y)]²
=(2x)²
=4x²

原式=(x+y)²-2(x+y)(x-y)+(x-y)²
=[(x+y)-(x-y)]²
=(2x)²
=4x²

=[(x+y)2-(x2-y2)]+[(x-y)2-(x2-y2)]
=(x+y)[(x+y)-(x-y)]+(x-y)[(x-y)-(x+y)]
=4y2
公式编辑器好久没用了，只好这么弄了，希望能够看懂，带2的都是表示平方啊。。。