(1)x^6+64y^6+12x^2y^2-1(2)4m^2-14mx+49nx-14mn(3)a^2b^2c-ab^3c+a^2bc^2-ab^2c^2(4)x^5-x^3-x^2-1(5)1+a+b+c+ab+bc+ac+abc(6)ab(c^2-d^2)-cd(a^2-b^2)(7)(x^2+1)^2-x^2+x(x-2)(x^2+x+1)
(1)x^6+64y^6+12x^2y^2-1
(2)4m^2-14mx+49nx-14mn
(3)a^2b^2c-ab^3c+a^2bc^2-ab^2c^2
(4)x^5-x^3-x^2-1
(5)1+a+b+c+ab+bc+ac+abc
(6)ab(c^2-d^2)-cd(a^2-b^2)
(7)(x^2+1)^2-x^2+x(x-2)(x^2+x+1)