Выражение (x^2-7y^3)^2+(x^2+7y^3)^2 (2,3a-7b^3)(2,3+,3a+7b^3)^2

(x^2-7y^3)^2+(x^2+7y^3)^2 =x^4-14x^4y³+49y^6+x^4-14x^4y³+49y^6=
=2x^4+98y^6
(2,3a-7b^3)(2,3a+7b^3)-(2,3a+7b^3)^2=(2,3a+7b³)(2,3a-7b³-2,3a-7b³)=
=(2,3a+7b³)*(-14b³)=-32,2ab³-98b^6