cd=10
Step-by-step explanation
Step 1
the speed of an object is the distance it moved in a given time
![\text{speed}=\frac{dis\tan ce}{\text{time}}](https://img.qammunity.org/2023/formulas/mathematics/college/huldyzh53u3mhhv7q7e49s8crk801t4fno.png)
Let
c represents the speed in miles per hour
d represents the time in hours
distance=10 miles
Then
Step 2
replace
![\begin{gathered} \text{speed}=\frac{dis\tan ce}{\text{time}} \\ \\ c=\frac{10\text{ miles}}{d} \\ \text{Multiply both sides by d} \\ cd=\frac{10\text{ miles}}{d}\cdot d \\ cd=10\text{ miles} \\ cd=10 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/3ibmaoys7pidfzg1m8tiw72dc6feup2wpy.png)
so, the answer is
C. cd=10
I hope this helps you.