Answer:
x≤3.6
Explanation:
First, lets simplify the equation:
5x+3≤21
5x≤18
x≤18/5
x≤3.6
To draw this on the number line, draw a filled in circle 6/10 to the right of 3 and 4/10 to the left of 4. Then draw an arrow pointing to the left.
I hope this solution was useful. Happy mathing!