\[\boxed{\text{24\ (24).\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
Пояснение.
Решение.
\[1)\ 7a^{2} - 7 = 7\left( a^{2} - 1 \right) =\]
\[= 7 \cdot (a - 1)(a + 1)\]
\[2)\ 3b^{3} - 3b = 3b\left( b^{2} - 1 \right) =\]
\[= 3b(b - 1)(b + 1)\]
\[3)2x^{3} - 2xy^{2} = 2x\left( x^{2} - y^{2} \right) =\]
\[= 2x(x - y)(x + y)\]
\[4) - 8a^{5} + 8a^{3} - 2a =\]
\[= 2a\left( - 4a^{4} + 4a^{2} - 1 \right) =\]
\[= - 2a\left( 2a^{2} - 1 \right)^{2}\]
\[5)\ x - 4y + x^{2} - 16y^{2} =\]
\[= (x - 4y) + \left( x^{2} - 16y^{2} \right) =\]
\[= (x - 4y) + (x - 4y)(x + 4y) =\]
\[= (x - 4y)(1 + x + 4y)\]
\[6)\ ab^{6} - ab^{4} - b^{6} + b^{4} =\]
\[= ab^{4}\left( b^{2} - 1 \right) - b^{4}\left( b^{2} - 1 \right) =\]
\[= \left( b^{2} - 1 \right)\left( ab^{4} - b^{4} \right) =\]
\[= b^{4}(b - 1)(b + 1)(a - 1)\]