[tex]30b^4 - 45b^3 - 10b^2 + 15b \\ \\ GCF = 5b \\ \\ 5b ( \frac{30b^4}{5b} + \frac{-45b^3}{5b} + \frac{-10b^2}{5b} + \frac{15b}{5b}) \\ \\ 5b(6b^3 - 9b^2 - 2b + 3) \\ \\ 5b(3b^2(2b-3)-(2b-3)) \\ \\ 5b(2b - 3)(3b^2 - 1) \\ \\ [/tex]
The final result is: 5b(2b - 3)(2b² - 1).