**Real world uses for linear functions include solving problems and finding unknowns in engineering, economics and finances.** A linear function describes a gradual rate of change, either positive or negative. When drawn, it presents a straight line.

Linear functions are a mathematical concept often taught first in an Algebra I class. Specific real world problems that can be solved using a linear function include:

- predicting equipment rental cost given a rate and rental period
- calculating profit for a small business
- taxes due on a particular amount of income
- in structural engineering design

Some real world examples with corresponding linear functions are:

- To convert a temperature from Celsius to Fahrenheit: F = 1.8C + 32
- To calculate the total monthly income for a salesperson with a base salary of $1,500 plus a commission of $400/unit sold: I = 400T + 1,500, where T represents the total number of units sold