Answer:
[tex]b<4[/tex]
Step-by-step explanation:
[tex]20b<80[/tex]
[tex]\frac{20b}{20}<\frac{80}{20}[/tex] (Divide both sides of the inequality by [tex]20[/tex] to get rid of [tex]b[/tex]'s coefficient)
[tex]b<4[/tex] (Simplify)
Hope this helps!