Let's generate an equation from the relationships found in the given scenario,
We get,
![\text{ 5 + 3.25x = 21.25}](https://img.qammunity.org/2023/formulas/mathematics/college/vo3a68aom5dk7kereiqf1q1v2gfczof698.png)
This equation reflects Trina's expenses during her indoor rock climbing. She spent an entrance fee of $5 and a rate of $3.25 per hour climb with a total expense of $21.25.
Where,
x = the number of hours Trina climbed.
Let's now compute how long did Trina use the indoor rock climbing facility.
![\text{ 5 + 3.25x = 21.25}](https://img.qammunity.org/2023/formulas/mathematics/college/vo3a68aom5dk7kereiqf1q1v2gfczof698.png)
Applying the Rule of Additive Inverse Property, we get,
![\text{ 5 + 3.25x - 5 = 21.25 - 5}](https://img.qammunity.org/2023/formulas/mathematics/college/6rvdwmnb2dpk7ba2tcqquiksuig3dzbaxc.png)
![\text{ 3.25x = 16.25 }\rightarrow\text{ x =}(16.25)/(3.25)](https://img.qammunity.org/2023/formulas/mathematics/college/kbqbj4df8om8rycwd01o8um1w3veljfsco.png)
![\text{ x =5}](https://img.qammunity.org/2023/formulas/mathematics/college/c77otom0ae2d8dlatgsmfh8vlhfwpksk2x.png)
Therefore, Trina spent 5 hours in the indoor rock climbing facility.
If Ralph wants to spend the same amount of money, he must use the indoor rock climbing facility for 5 hours.