factor the following
1. 26x^3y^2+52x^2y^3-39x^2yz
2. 4x(3m-4n)-6y(3m-4n)
3. (a+2b)(x-3y)+(3c+4d)(x-3y)
4. 25a^2b^4-64c^6
5. 27x^2-12y^2