Fill in the missing number after simplifying the following division problem.

$\displaystyle\frac{{{55}{{b}}^{{8}}-{40}{{b}}^{{5}}-{35}{b}}}{{{10}{{b}}^{{3}}}}=\frac{{{11}{{b}}^{{5}}}}{{{2}}}-{4}{{b}}^{{2}}-\frac{{{7}}}{{?{{b}}^{{2}}}}\usepackage{cmbright}\Huge\$