Решебник по алгебре 7 класс Мерзляк Задание 718

\[\boxed{\text{718\ (718).\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]

\[1)\ 15\text{cx} + 2\text{cy} - \text{cxy} - 30c =\]

\[= 15c(x - 2) - \text{cy}(x - 2) =\]

\[= (x - 2)\left( 15c - \text{cy} \right) =\]

\[= c \cdot (15 - y)(x - 2)\]

\[2)\ 35a² - 42ab + 10a^{2}b - 12ab^{2} =\]

\[= 5a^{2}(7 + 2b) - 6ab(7 + 2b) =\]

\[= (7 + 2b)\left( 5a^{2} - 6ab \right) =\]

\[= a \cdot (7 + 2b)(5a - 6b)\]

\[3)\ x^{3} + x^{2}y + x^{2} + xy =\]

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

\[= (x + y)\left( x^{2} + x \right) =\]

\[= x \cdot (x + y)(x + 1)\]

\[4)\ mn^{4} - n^{4} + mn^{3} - n^{3} =\]

\[= n^{4}(m - 1) + n^{3}(m - 1) =\]

\[= (m - 1)\left( n^{4} + n^{3} \right) =\]

\[= n^{3}(m - 1)(n + 1)\]