Q169 :

b^2 c^4 x^4 y^2+a^2 c^4 x^3 y^3-b^2 c^4 x^3 y^3-a^2 c^4 x^2 y^4-b^4 c^2 x^4 y z+b^2 c^4 x^4 y z-b^4 c^2 x^3 y^2 z+a^4 c^2 x^2 y^3 z+a^4 c^2 x y^4 z-a^2 c^4 x y^4 z-b^4 c^2 x^4 z^2+b^2 c^4 x^3 y z^2-a^2 c^4 x y^3 z^2+a^4 c^2 y^4 z^2-a^2 b^4 x^3 z^3+b^4 c^2 x^3 z^3-a^4 b^2 x^2 y z^3+a^2 b^4 x y^2 z^3+a^4 b^2 y^3 z^3-a^4 c^2 y^3 z^3+a^2 b^4 x^2 z^4-a^4 b^2 x y z^4+a^2 b^4 x y z^4-a^4 b^2 y^2 z^4=0