distance(15 min)=30b
Step-by-step explanation
Step 1
Brianna runs in the park every day at the average rate of b meters per minute, it means for every minute she run b meters
![\text{rate}=b(mt)/(\min )](https://img.qammunity.org/2023/formulas/mathematics/college/zfxrrecgdzq4hgko2fliq5w5mt039zql1u.png)
then
distance= b (mt)
time=1 minute
rate= b mt per minute.
Step 2
now, 15 minutes she runs double her regular speed ( it is 2b)
time=15 minutes
then
time=15
rate=2b
![\begin{gathered} \text{rate}=\frac{dis\tan ce}{\text{time}} \\ 2b=\frac{dis\tan ce}{\text{time}} \\ 2b\cdot\text{time}=\text{distance}1 \\ 15\cdot2b=\text{ distance 1} \\ 30b=\text{distance 1} \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/buabmyils4hvw0cuopg7gwcx0m5h3q225a.png)
Step 3
for the other 45 minutes, she runs at her regular rate (b)
time= 45 minutes=0.75 hours
rate=b
distance=distance2
![\begin{gathered} \text{rate}=\frac{dis\tan ce}{\text{time}} \\ \text{b}=\frac{dis\tan ce2}{45\text{ hours}} \\ \text{45}\cdot b=\text{distance 2} \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/83tg4f50zgxz4r3udtuodbdrf8v1im8t19.png)