Answer: -2b-4
Ok, so I assume you meant b-4-3b. If not, then B-4-3b is the best you can get, since B and b are different in math.
Anyways, we can rearrange b-4-3b into b-3b-4. Calculating b-3b = -2b. That means -2b-4 is the answer.
Hope that helped,
-sirswagger21
