Answer:
The beach house with the highest rate per night is House 2.
They charge $249 per night
Step-by-step explanation:
Given that the graph represent the rate at which House 1 charges;
We need to derive the equation for house 1.
Recall that the slope-intercept equation of a straight line can be represented by;
![y=mx+b](https://img.qammunity.org/2023/formulas/mathematics/high-school/smsb8cbft03lwblmi49nf2l6jby2ofxzws.png)
where;
m = slope
b = y-intercept
Fro the given graph the y-intercept is at y=200, so;
![b=200](https://img.qammunity.org/2023/formulas/mathematics/college/n0iwmsa6r9xow1nb86k0tzwmxp1j4wh64y.png)
we can also calculate the slope m using the formula;
![m=(\Delta y)/(\Delta x)=(y_2-y_1)/(x_2-x_1)](https://img.qammunity.org/2023/formulas/mathematics/college/qcwvs4hqqwwac8pb7570w0p2cei13pwdmn.png)
Substituting the coordinates on the graph;
![(0,200)\text{ and (4,1000)}](https://img.qammunity.org/2023/formulas/mathematics/college/3zsgv978rqr9hlbq6aaxglwvqht2h6yn51.png)
we have;
![\begin{gathered} m=(1000-200)/(4-0) \\ m=(800)/(4) \\ m=200 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/tzhb506pqnfumnvypkpwwj668gps7a8afl.png)
Therefore, we can write the equation for House 1 as;
![y=200x+200](https://img.qammunity.org/2023/formulas/mathematics/college/qum3xhfi76lmzmcd7nitt6wx92lgbtezrs.png)
So, the equation for each house is;
![\begin{gathered} \text{House 1;} \\ y=200x+200 \\ \text{House 2;} \\ y=249x+100 \\ \text{House 3;} \\ y=230x+115 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/gvhhxg4eeyr2twohms8fisv3byjlp7lv96.png)
where y is the total cost, x is the number of nights.
From the three equations, the beach house with the highest rate is House 2.
They charge $249 per night