Please help
10 points and I will give you brainliest

Answer:
-10
Step-by-step explanation:
5ab-4bc+8ab+9=
1) 5ab+8ab=13ab
2) 13ab-4bc=b(13a-4c)
3) b(13a-4c)+9= (-1)( 13×3-4×5)+9= -19+9= -10