Answer
$x\geq 2$
Please see image
Work Step by Step
$ 18+2x\leq 9x+4\qquad$ ...add $-9x$ to each side of the inequality.
$ 18+2x-9x\leq 9x+4-9x\qquad$ ...simplify.
$ 18-7x\leq 4\qquad$ ...add $-18$ to each side of the inequality.
$ 18-7x-18\leq 4-18\qquad$ ...simplify.
$-7x\leq-14\qquad$ ...divide each side of the inequality with $-7$.
...dividing with a negative inverts the inequality sign.
$x\geq 2$
The solutions of the given inequality are all real numbers greater than or equal to $2$.
Use a solid dot in the graph to indicate $2$ is a solution.