作业帮当x=-1 y=-2时求代数式[2x^2-(x+y)(x-y)][(-x-y)(-x+y)+2y^2]的值
来源：学生作业帮助网 编辑：作业帮 时间：2024/04/29 12:41:19
![当x=-1 y=-2时求代数式[2x^2-(x+y)(x-y)][(-x-y)(-x+y)+2y^2]的值](/uploads/image/z/1671243-51-3.jpg?t=%E5%BD%93x%3D-1+y%3D-2%E6%97%B6%E6%B1%82%E4%BB%A3%E6%95%B0%E5%BC%8F%5B2x%5E2-%28x%2By%29%28x-y%29%5D%5B%28-x-y%29%28-x%2By%29%2B2y%5E2%5D%E7%9A%84%E5%80%BC)
当x=-1 y=-2时求代数式[2x^2-(x+y)(x-y)][(-x-y)(-x+y)+2y^2]的值
当x=-1 y=-2时求代数式[2x^2-(x+y)(x-y)][(-x-y)(-x+y)+2y^2]的值
当x=-1 y=-2时求代数式[2x^2-(x+y)(x-y)][(-x-y)(-x+y)+2y^2]的值
[2x^2-(x+y)(x-y)][(-x-y)(-x+y)+2y^2]
=[2x^2-x^2+y^2][x^2-y^2+2y^2]
=(x^2+y^2)^2
=(1+4)^2
=25