To determine where the open circle would be located in the piecewise function given, we need to evaluate the transition point at \( x = 10 \).
The function is defined as follows:
- For \( x < 10 \): \( f(x) = 2.5x \)
- For \( x \geq 10 \): \( f(x) = 2.25x \)
At \( x = 10 \):
- When using the first part of the function (for \( x < 10 \)), we calculate \( f(10) = 2.5 \times 10 = 25 \).
- When using the second part of the function (for \( x \geq 10 \)), we calculate \( f(10) = 2.25 \times 10 = 22.5 \).
Since the function changes at \( x = 10 \), it means that the point \( (10, 25) \) from the first part does not actually belong to the function (as it is defined for \( x < 10 \)), and thus it will have an open circle.
Therefore, the point that has an open circle is:
\((10, 25)\).