Answer
$ b\geq 10$
The graph is shown below.
Work Step by Step
The given inequality is
$\Rightarrow 18\leq 3(b-4)$
Divide each side by $-3$.
$\Rightarrow \frac{18}{3}\leq \frac{3(b-4)}{3}$
Simplify.
$\Rightarrow 6\leq b-4$
Add $4$ to each side.
$\Rightarrow 6+4\leq b-4+4$
Simplify.
$\Rightarrow 10\leq b$
Hence, the solution is $ b\geq 10$.
Use a close circle because $10$ is a solution.
Shade the number line on the right side.
