\[\boxed{\text{23\ (23).\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
Пояснение.
Решение.
\[1)\ x^{2} - 9 = (x - 3)(x + 3)\]
\[2)\ 25 - 4y^{2} = (5 - 2y)(5 + 2y)\]
\[3)\ 36m^{2} - 49n^{2} =\]
\[= (6m - 7n)(6m + 7n)\]
\[4)\ a^{2}b^{2} - 81 = (ab - 9)(ab + 9)\]
\[5)\ 100m^{6} - 1 =\]
\[= (10m^{3} - 1)(10m^{3} + 1)\]
\[6)\ a^{10} - b^{6} = (a^{5} - b^{3})(a^{5} + b^{3})\]
\[7)\ c^{3} - d^{3} = (c - d)(c^{2} + cd + d^{2})\]
\[8)\ a^{3} + 8 = (a + 2)(a^{2} - 2a + 4)\]
\[9)\ 27m^{6} - n^{9} =\]
\[= (3m^{2} - n^{3})(9m^{4} + 3m^{2}n^{2} + n^{6})\]