Answer:
4b^4 + 6b^3 + 13b^2 + 10b -1
Step-by-step explanation:
4b^4 + 12b^3 + 5b^2 + 6 - (6b^3 – 8b^2 – 10b + 7)
= 4b^4 + 12b^3 + 5b^2 + 6 - 6b^3 + 8b^2 + 10b - 7
= 4b^4 + ( 12b^3 - 6b^3) + (5b^2 + 8b^2) + 10b + (6 - 7)
= 4b^4 + 6b^3 + 13b^2 + 10b -1
