Answer:
19, 20, 21
Step-by-step explanation:
You can trial-and-error this where you test each answer out step-by-step or you can graph it and you'll see it will be a line for x = 21 and a shaded region to the left of that (if you get what I mean) and from there, any point on the line x = 21 or any point in the shaded region, will be a viable solution.
Simplifying,
[tex]-\frac{2}{3}s+13>=-1\\-\frac{2}{3}s>=-14\\\frac{2}{3}s=<14\\s=<21[/tex]
s ≤ 21
