Work Shown
4x - 7 ≤ 9
4x ≤ 9+7
4x ≤ 16
x ≤ 16/4
x ≤ 4
Explanation
Add 7 to both sides. Then divide both sides by 4 to isolate x. Dividing both sides by a positive number will not flip the inequality sign. This only occurs when dividing both sides by a negative number.
To graph this on a number line, plot a filled in circle at 4. Then shade to the left. This visually describes all numbers x such that x = 4 or x < 4. We include the endpoint. If the "or equal to" wasn't part of the inequality sign, then we would exclude the endpoint with an open hole.