(2,3а-7b^3)(2,3a+7b^3)-(2,3a+7b^3)^2=
=-98b^6 ................
(2,3а-7b^3)(2,3a+7b^3)=5.29a²-49b∧6 5.29a²-49b∧6-(5.29a²+32/2ab³+49b∧6)=5.29a²-49b∧6--5.29a²-32.2ab³-49b∧6=-98b∧6-32.2ab³ ответ:-98b∧6-32.2ab³