Answer:
[tex]\boxed{b = -3}[/tex]
Step-by-step explanation:
[tex]\sf -11b+7 = 40\\Subtracting\ 7\ to\ both\ sides\\-11b = 40-7\\-11b = 33\\Dividing\ both\ sides \ by \ -11\\ b = 33/-11\\b = -3[/tex]