Ответ:
1)(X-3)(X+3)
2)5^2-2^2y^2=5^2-(2y)^2=(5-2y)•(5+2y)
3)6^2m^2-7^2n^2=(6m)^2-(7n)^2=(6m-7n)•(6m+7n)
4)(ab)^2-9^2=(ab-9)•(ab+9)
5)10^2m^2•3-1^2=10^2•(m^3)^2-1^2=(10m^3-1)•(10m^3+1)
6)a^2•5-b^2•3=(a^5)^2-(b^3)^2=(a^5-b^3)•(a^5+b^3)
7)c^3-d^3=(c-d)•(c^2+cd+d^2)
8)(a+2)•(a^2-2a+4)
9)3^3m^3•2-n^3•3=(3m^2)^3-(n^3)^3=(3m^2-n^3)•((3m^2)^2+3m^2n^3+(n^3)^2)=(3m^2-n^3)•(9m^4+3m^2n^3+n^6)
Вот