ГДЗ по алгебре 7 класс Макарычев ФГОС Задание 936

\[\boxed{\text{936.}\text{\ }еуроки - ответы\ на\ пятёрку}\]

\[\textbf{а)}\ 4 \cdot (m - n)^{2} + 4m(m - n) =\]

\[= 4 \cdot \left( m^{2} - 2mn + n^{2} \right) +\]

\[+ 4m² - 4mn =\]

\[= 4m^{2} - 8mn + 4n^{2} + 4m^{2} -\]

\[- 4mn = 8m^{2} - 12mn + 4n²\]

\[\textbf{б)}\ 5x(x - y) - 2 \cdot (y - x)^{2} =\]

\[= 5x^{2} - 5xy - 2 \cdot\]

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

\[= 5x^{2} - 5xy - 2y^{2} + 4xy -\]

\[- 2x^{2} = 3x^{2} - xy - 2y²\]

\[\textbf{в)}\ (y + 7)^{2} - 2 \cdot\]

\[\cdot (y + 10)(y + 4) =\]

\[= \left( y^{2} + 14y + 49 \right) - 2 \cdot\]

\[\cdot \left( y^{2} + 4y + 10y + 40 \right) =\]

\[= y^{2} + 14y + 49 - 2y^{2} - 8y -\]

\[- 20y - 80 = - y^{2} - 14y - 31\]

\[\textbf{г)}\ (x - 5)(6 + 4x) - 3 \cdot\]

\[\cdot (1 - x)^{2} = 6x + 4x^{2} - 30 -\]

\[- 20x - 3 \cdot \left( 1 - 2x + x^{2} \right) =\]

\[= 4x^{2} - 14x - 30 - 3 + 6x -\]

\[- 3x^{2} = x^{2} - 8x - 33\]