Factorizar:
1. 7abc – 35abc2
2. 2a4b – 4ab4 – 6a4b4
3. 5a4b4 + 25a8b3 – 30a9b4
4. 2 ( a + b ) + x ( a + b )
5. 3b ( 2x + 3 ) + 2x + 3
6. x2 + y2 – 5y ( x2 + y2 ) ​