How to Graph Linear Equation Word Problems
Linear equations form a straight line when graphed. Graphing linear equations is simple, especially when your equation is expressed in slope-intercept form (y = mx + b). However, sometimes you will need to write the linear equation based on a situation explained in a word problem. Although word problems often seem intimidating at first glance, graphing linear equations expressed in word problems is a simple process.
Other People Are Reading
Instructions
-
-
1
Identify the x- and y-variables. The x-variable, or independent variable, does not depend on y while the y-variable, or dependent variable, changes according to the value of x. For example, if your word problem is about how many hours a teenager needs to work to buy an $800 car, the independent variable would be the hours worked, and the dependent variable would be the amount earned.
-
2
Determine the slope if possible. The slope, or rise over run, is the change in the y-variable when the x-variable changes by one. For example, if the teenager earns $10 an hour, the slope would be 10. If you can't identify the slope, don't worry; you can solve for it with the information you are given.
-
-
3
Write out the equation in slope-intercept form. For example, in our word problem, y = 800, and the slope is 10. Assuming the teenager had no savings, the y-intercept is 0; if she started out with a certain amount saved toward the car, that would be the y-intercept. The equation is 800 = 10x, so x = 80.
-
4
Solve for different points on the graph by substituting different values for x and solving for y. For example, when the teenager has worked no hours (x = 0), she has no wages, so (0, 0) is one coordinate. After working two hours, she has $20, so (2, 20) is another point. After working 15 hours, she has $150, so (15, 150) is another coordinate.
-
5
Plot the points and draw a line to connect them.
-
6
Label the axes with the correct units of measurement. For example, in our word problem, the x-axis is hours worked, and the y-axis is money earned.
-
1
