ГДЗ по алгебре 7 класс Макарычев ФГОС Задание 993

\[\boxed{\text{993.}\text{\ }еуроки - ответы\ на\ пятёрку}\]

\[\textbf{а)}\ (x + y + 1)(x + y - 1) =\]

\[= (x + y)^{2} - 1 = x^{2} +\]

\[+ 2xy + y^{2} - 1\]

\[\textbf{б)}\ (m + n - 3)(m + n + 3) =\]

\[= (m + n)^{2} - 9 = m^{2} +\]

\[+ 2mn + n^{2} - 9\]

\[\textbf{в)}\ (a - b - 5)(a - b + 5) =\]

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

\[- 2ab + b^{2} - 25\]

\[\textbf{г)}\ (c - d + 8)(c - d - 8) =\]

\[= (c - d)^{2} - 64 = c^{2} -\]

\[- 2cd + d^{2} - 64\]

\[\textbf{д)}\ (p + 2q - 3)(p - 2q - 3) =\]

\[= (p - 3)^{2} - 4q^{2} = p^{2} -\]

\[- 6p - 4q^{2} + 9\]

\[\textbf{е)}\ (a - 3x + 6)(a + 3x + 6) =\]

\[= (a + 6)^{2} - 9x^{2} = a^{2} +\]

\[+ 12a - 9x^{2} + 36\ \]