# 4 – Linear Equations

• As a chairlift carries you up a snowy mountainside, you’re anticipating the thrills to come: the icy wind in your face, the exhilarating speed, the other skiers flying past. You may not be thinking in terms of linear equations—but you could be.
• If you were to plot the chair’s movement on a graph, what would it look like? The more you move forward, the higher you go up.
• How would the equation change if the mountain were steeper? Would it change if the chair moved faster?
• What kind of equation would represent the line you create when you ski down?
• Linear equations can represent slopes that are easy to visualize, such as a hillside, but they can also show relationships between any two variables that create a straight line when plotted on a graph.
• How does a farmer’s crop production change based on rainfall?
• How do store profits increase as the holidays approach?
• How much would you pay for a shirt that’s 20 percent off? How about 25? Or 30?
• In this unit, you’ll learn about calculating slopes of lines, linear equations and inequalities, and how they can help you solve a variety of real-world problems.