Start with the inequality: -5 + 4s < -9.
- Add 5 to both sides to isolate the term with s:
-5 + 4s + 5 < -9 + 5, which simplifies to 4s < -4. - Divide both sides by 4 (since 4 is positive, the inequality direction does not change):
s < -4/4, so s < -1.
Final answer: s < -1 (interval notation: (-∞, -1)).
Quick check: choose s = -2: -5 + 4(-2) = -13, and -13 < -9 is true. Choose s = 0: -5 < -9 is false. These checks confirm the solution.