化简(x+y+z)^2-(-x+y+z)^2+(x-y+z)^2-(x+y-z)^2
题目
化简(x+y+z)^2-(-x+y+z)^2+(x-y+z)^2-(x+y-z)^2
答案
利用A^2-B^2=(A+B)(A-B)即可.(x+y+z)^2-(-x+y+z)^2+(x-y+z)^2-(x+y-z)^2=[(x+y+z)^2-(-x+y+z)^2]+[(x-y+z)^2-(x+y-z)^2]={[(x+y+z)+(-x+y+z)]*[(x+y+z)-(-x+y+z)]}+{[(x-y+z)+(x+y-z)]*[(x-y+z)-(x+y-z)]}=[(2y+2z)*...
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