Data:
City 1: A
City 2: B
Tax (r):
B= 7%
A=5%
![\begin{gathered} A=C_A+C_A(0.05) \\ B=C_B+C_B(0.07) \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/ju7dmqlwdp9zo1hsf0w3lm9lsjoauujhdc.png)
Cost without tax: C
Tax: C( r %)
The hotel charge before tax in the second city was $1500 lower than the first:
![C_B=C_A-1500](https://img.qammunity.org/2023/formulas/mathematics/college/tbdwr5dgis86h39ocmxtsvckue8w45xz7k.png)
The hotel tax paid for the two cities was $435:
![C_A(0.05)+C_B(0.07)=435](https://img.qammunity.org/2023/formulas/mathematics/college/kie71tg92casbsw2yofkiw5prjk261fcy9.png)
Use the equations above to find the hotel charge (CA and CB) in each city:
1. Substitute in the second equation the CB for the value of CB in the first equation:
![C_A(0.05)+(C_A-1500)(0.07)=435](https://img.qammunity.org/2023/formulas/mathematics/college/3wwq8s48cryqdho58p29y0gdjz4wj7ctu6.png)
2. Solve CA:
![\begin{gathered} \text{0}.05C_A+0.07C_A-105=435 \\ \\ 0.12C_A-105=435 \\ \\ 0.12C_A=435+105 \\ \\ 0.12C_A=540 \\ \\ C_A=(540)/(0.12) \\ \\ C_A=4500 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/gz2qtyv6lwa077kcgyxyrmg67g3qg21lu7.png)
3. Use the value you find for CA to find CB:
![\begin{gathered} C_B=C_A-1500 \\ C_B=4500-1500 \\ \\ C_B=3000 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/dy8b4o33ryfxah1dr0n3q93w9v6sd1wrq4.png)
Then, the charge before tax of the hotel in first city (CA) is $4500 and in the second hotel (CB) is $3000