怎样计算:(x+y+z)*(-x+y+z)*(x-y+z)*(x+y-z) 怎样把括号去掉?
问题描述:
怎样计算:(x+y+z)*(-x+y+z)*(x-y+z)*(x+y-z) 怎样把括号去掉?
答
原式=[x^2-(y-z)^2]*[(y-z)^2-x^2]
=-[x^2-(y-z)^2]^2
=-x^4+2x^2(y-z)^2-(y-z)^4