## Algebra 2 Common Core

If $y$ equals the total cost and $x$ equals the total miles: (a) Proxy car rental: $y=.32x+18$ (b) YourPal car rental: $y=.36x+12$ (c) Proxy
To find the function of a rental company, we multiply the cost per mile by $x$ and add the surcharge. We multiply the cost per mile by the total miles to get the amount paid from the miles. $\frac{cost}{mile}\times mile=cost$. We then add the surcharge to finish the function. (c) We substitute 820 into the functions Proxy: $.32(820)+18=280.4$ YourPal: $.36(820)+12=307.2$ Proxy offers a better deal.