I'm assuming that the last term in the numerator is just 46, not 46b...
Using long division:
5b^2 + (-2b) + 9
___________________________
6b+5/ 30b^3 + 13b^2 + 44b + 46
30b^2 + 25b^2
=============
-12b^2 + 44b
-12b^2 + (-10b)
===============
54b + 46
54b + 45
========
1
So
P.S. If the last term of the numerator was 45, then there would be no remainder and the answer would just be