(x+y)²-2(x+y)(x-y)+(x-y)²(要求:写明原因、最简单的方法)
来源:学生作业帮助网 编辑:作业帮 时间:2024/06/30 01:45:46
![(x+y)²-2(x+y)(x-y)+(x-y)²(要求:写明原因、最简单的方法)](/uploads/image/z/531688-40-8.jpg?t=%28x%2By%29%26%23178%3B-2%28x%2By%29%28x-y%29%2B%28x-y%29%26%23178%3B%EF%BC%88%E8%A6%81%E6%B1%82%EF%BC%9A%E5%86%99%E6%98%8E%E5%8E%9F%E5%9B%A0%E3%80%81%E6%9C%80%E7%AE%80%E5%8D%95%E7%9A%84%E6%96%B9%E6%B3%95%EF%BC%89)
(x+y)²-2(x+y)(x-y)+(x-y)²(要求:写明原因、最简单的方法)
(x+y)²-2(x+y)(x-y)+(x-y)²(要求:写明原因、最简单的方法)
(x+y)²-2(x+y)(x-y)+(x-y)²(要求:写明原因、最简单的方法)
(x+y)²-2(x+y)(x-y)+(x-y)² [直接逆用完全平方公式(a-b)²=a²-2ab+b²,其中a=(x+y),b=(x-y)]
=[(x+y)-(x-y)]²
=[2y]²
=4y²