\[\boxed{\text{680\ (680).}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
Пояснение.
Решение.
\[\textbf{а)}\ \left( x^{2} + y \right)\left( x + y^{2} \right) =\]
\[= x^{3} + x^{2}y^{2} + yx + y^{3}\]
\[\textbf{б)}\ \left( m^{2} - n \right)\left( m^{2} + 2n^{2} \right) =\]
\[= m^{4} + 2m^{2}n^{2} - nm^{2} - 2n^{3}\]
\[\textbf{в)}\ \left( 4a^{2} + b^{2} \right)\left( 3a^{2} - b^{2} \right) =\]
\[= 12a^{4} - 4a^{2}b^{2} + 3a^{2}b^{2} - b^{4} =\]
\[= 12a^{4} - a^{2}b^{2} - b^{4}\]
\[\textbf{г)}\ \left( 5x^{2} - 4x \right)(x + 1) =\]
\[= 5x^{3} + 5x^{2} - 4x^{2} - 4x =\]
\[= 5x^{3} + x^{2} - 4x\]
\[\textbf{д)}\ (a - 2)\left( 4a^{3} - 3a^{2} \right) =\]
\[= 4a^{4} - 3a^{3} - 8a^{3} + 6a^{2} =\]
\(= 4a^{4} - 11a^{3} + 6a^{2}\)
\[\textbf{е)}\ \left( 7p^{2} - 2p \right)(8p - 5) =\]
\[= 56p^{3} - 35p^{2} - 16p^{2} + 10p =\]
\[= 56p^{3} - 51p^{2} + 10p\]