ГДЗ по алгебре 7 класс Макарычев ФГОС Задание 1019

\[\boxed{\text{1019.}\text{\ }еуроки - ответы\ на\ пятёрку}\]

\[\textbf{а)}\ (y + 5)\left( y^{2} - 5y + 25 \right) -\]

\[- y\left( y^{2} + 3 \right) = y^{3} + 125 - y^{3} -\]

\[- 3y = - 3y + 125\]

\[если\ \ y = - 2:\]

\[- 3y + 125 = - 3 \cdot ( - 2) +\]

\[+ 125 = 6 + 125 = 131.\]

\[\textbf{б)}\ x(x + 3)^{2} -\]

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

\[= x\left( x^{2} + 6x + 9 \right) - \left( x^{3} - 1 \right) =\]

\[= x^{3} + 6x^{2} + 9x - x^{3} + 1 =\]

\[= 6x^{2} + 9x + 1\]

\[если\ x = - 4:\ \]

\[6 \cdot ( - 4)^{2} + 9 \cdot ( - 4) + 1 =\]

\[= 96 - 36 + 1 = 61.\]

\[\textbf{в)}\ (2p - 1)\left( 4p^{2} + 2p + 1 \right) -\]

\[- p(p - 1)(p + 1) = 8p^{3} -\]

\[- 1 - p\left( p^{2} - 1 \right) =\]

\[= 8p^{3} - 1 - p^{3} + p =\]

\[= 7p^{3} + p - 1\]

\[если\ p = 1,5:\]

\[7 \cdot (1,5)^{3} + 1,5 - 1 = 23,625 +\]

\[+ 1,5 - 1 = 24,125.\ \]