X^4+Y^4+Z^4+1+8XYZ-2(Y^2*Z^2+X^2*Z^2+X^2*Y^2+X^2+Y^2+Z^2)
=X^4-2X^2*Z^2+Z^4+
X^4-2X^2*Y^2+Y^4+
Y^4-2Y^2*Z^2+Z^4-
(X^4+Y^4+Z^4+1+8XYZ+
X^2+Y^2+Z^2)
=(X^2-Z^2)+(Y^2-Z^2)+(X^2-Y^2)-
(X^4+2X^2+1+
Y^4+2Y^2+1+
Z^4+2Z^2+1)+
(X^2+Y^2+Z^2+3+8XYZ)
下次继续
X^4+Y^4+Z^4+1+8XYZ-2(Y^2*Z^2+X^2*Z^2+X^2*Y^2+X^2+Y^2+Z^2)
=X^4-2X^2*Z^2+Z^4+
X^4-2X^2*Y^2+Y^4+
Y^4-2Y^2*Z^2+Z^4-
(X^4+Y^4+Z^4+1+8XYZ+
X^2+Y^2+Z^2)
=(X^2-Z^2)+(Y^2-Z^2)+(X^2-Y^2)-
(X^4+2X^2+1+
Y^4+2Y^2+1+
Z^4+2Z^2+1)+
(X^2+Y^2+Z^2+3+8XYZ)
下次继续