lemme just add to @Konrad509's great reply above
[tex] \bf -4<3b+2\le 20\implies \stackrel{\textit{subtracting 2 from all sides}}{-6< 3b \le 18}\implies \stackrel{\textit{dividing all sides by 3}}{-\cfrac{6}{3}<\cfrac{3b}{3}\le \cfrac{18}{3}}
\\[2em]
~~~~~~~~~~-2< b \le 6 [/tex]
