Задание 2 Параграф 14 ГДЗ Рабочая тетрадь 1 Мерзляк Полонский 7 класс (Алгебра)

1) (c-8)(c+8);
2) (2ab+3)(2ab-3);
3) (5x-7y^2 )(5x+7y^2 );
4) (a^4+b^3 )(b^3-a^4 );
5) (6m^2-11p^5 )(11p^5+6m^2 );
6) (-9xy-z)(9xy-z).

1. $$ (c-8)(c+8)=c^2-8^2=c^2-64 $$
2. $$ (2ab+3)(2ab-3)=(2ab)^2-3^2=4a^2b^2-9 $$
3. $$ (5x-7y^2)(5x+7y^2)=(5x)^2-(7y^2)^2=25x^2-49y^4 $$
4. $$ (a^4+b^3)(b^3-a^4)=(b^3+a^4)(b^3-a^4)=(b^3)^2-(a^4)^2=b^6-a^8 $$
5. $$ (6m^2-11p^5)(11p^5+6m^2)=(6m^2-11p^5)(6m^2+11p^5) $$
   $$ =(6m^2)^2-(11p^5)^2=36m^4-121p^{10} $$
6. $$ (-9xy-z)(9xy-z)=-(9xy+z)(9xy-z) $$
   $$ =-\big((9xy)^2-z^2\big)=z^2-81x^2y^2 $$

Ответ

1) $$c^2-64$$; 2) $$4a^2b^2-9$$; 3) $$25x^2-49y^4$$; 4) $$b^6-a^8$$; 5) $$36m^4-121p^{10}$$; 6) $$z^2-81x^2y^2$$.