The answer is: option C) 3x + 7.5 ≤ 9
The number sentence that has exactly one solution is: 3x + 7.5 ≤ 9
This can be seen by graphing the inequality, as shown below: The solution is the point where the graph intersects the x-axis, which is at x = 0.5.
The other answer choices are incorrect:
x + 5.4 > 8: This inequality has infinitely many solutions.
14(x – 5) = 13: This inequality has no solutions.
12x – 19 > 24: This inequality has infinitely many solutions.
Therefore, the answer is: 3x + 7.5 ≤ 9