Answer:
3(3b-2)
Step-by-step explanation:
(2bx2+5b-4)+(4bx2-8b-2)
(4b+5b-4)+(8b-8b-2)
4b+5b-4+8b-8b-2
17b-6-8b
9b-6
___3(3b-2)___