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x4+y4+z4-2x2y2-2y2z2-2z2x2.

题目详情
x4+y4+z4-2x2y2-2y2z2-2z2x2
▼优质解答
答案和解析
原式=x4-2x2y2+y4-2y2z2-2z2x2+z4
=(x2-y22-2z2(x2+y2)+z4
=(x2-y22-2z2(x2-y2)+z4-4x2y2
=(x2-y2-z22-4x2y2
=(x2-y2-z2-2yz)(x2-y2-z2+2yz)
=[x2-(y+z)2][x2-(y-z)2]
=(x+y+z)(x-y-z)(x+y-z)(x-y+z).