Algebra and its applications

Research an application of algebra and algebraic modeling.  For example, you could research carbon dating to determine the age of an artifact… or calculating the time it will take for you to drive from your house to Las Vegas on your annual road trip…  or determining what interest rate you can handle for a new car loan in order to keep your monthly payments below a certain amount, etc.  Discuss the way algebra would be used to address your example and provide an example of a formula that would be used in the process.  Provide at least one reference.