To find the rate of change in the context of the equation \(-15 + 9.5\), we first calculate the sum:
\[ -15 + 9.5 = -5.5 \]
The rate of change typically refers to how much one quantity changes in relation to another. However, in this case, we simply have a calculation rather than a change over time or another variable.
If you are looking for the rate of change between two points, we would need more context or a second quantity to compare against. Could you clarify what you're looking for regarding the rate of change?