We are given the following function:
![h\mleft(x\mright)=-x^2-9x+23](https://img.qammunity.org/2023/formulas/mathematics/high-school/dkl2bszg6e1o3g1gaxekszpoylqrfd4odp.png)
We are asked to determine the rate of change of the function in the interval:
![-8≤x≤0](https://img.qammunity.org/2023/formulas/mathematics/high-school/ybf0vbxlnq5453h97wgquo1g3s2s7njwuf.png)
To do that we will use the following formula:
![r=(f(b)-f(a))/(b-a)](https://img.qammunity.org/2023/formulas/mathematics/college/vp46l3c395bnttiuntt71lpx8l80vv9ovt.png)
Where "a" and "b" are the extreme values of the function. -
We have that "a = -8" and "b = 0". Now, we substitute the value of "a" in the function:
![\begin{gathered} f(-8)=-(-8)^2-9(-8)+23 \\ \\ f(-8)=31 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/high-school/futrgupmu3a695tuylf34fcsh6wrhmz9pf.png)
Now, we substitute the value of "b":
![\begin{gathered} f(0)=-(0)^2-9(0)+23 \\ \\ f(0)=23 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/high-school/6o6aub30krd6xyaxlmrnyrihtv3meq47qe.png)
Now, we substitute the values in the formula for the rate of change:
![r=(23-31)/(0-(-8))=-1](https://img.qammunity.org/2023/formulas/mathematics/high-school/nuzdfx51xzgadsskf8jlileus9bnemuym5.png)
Therefore, the rate of change is -1