In the expansion of

(2b24b5)(2b4)(2b23b+4)\displaystyle {\left({2}{b}^{{2}}-{4}{b}-{5}\right)}{\left(-{2}{b}-{4}\right)}{\left({2}{b}^{{2}}-{3}{b}+{4}\right)}

the b3\displaystyle {b}^{{3}} term is