Решебник по алгебре 7 класс Мерзляк Задание 501

\[\boxed{\text{501\ (501).\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]

Пояснение.

Решение.

\[1)\ (c - 2)(c + 2) = c^{2} - 4\]

\(2)\ (12 - x)(12 + x) = 144 - x^{2}\)

\[3)\ (3x + y)(3x - y) =\]

\[= (3x)^{2} - y^{2} = 9x^{2} - y^{2}\]

\[4)\ (6x - 9)(6x + 9) =\]

\[= (6x)^{2} - 9^{2} = 36x^{2} - 81\]

\[5)\ (x + 7)(7 - x) = 7^{2} - x^{2} =\]

\[= 49 - x^{2}\]

\[6)\ (5a - 8b)(5a + 8b) =\]

\[= (5a)^{2} - (8b)^{2} = 25a^{2} - 64b^{2}\]

\[7)\ (8m + 2)(2 - 8m) =\]

\[= 2^{2} - (8m)^{2} = 4 - 64m^{2}\]

\[8)\ (13c - 14d)(14d + 13c) =\]

\[= (13c)^{2} - (14d)^{2} =\]

\[= 169c^{2} - 196d^{2}\]