How to plot straight line graphs

Home learning focus

Learn how to plot straight line graphs.

This lesson includes:

  • one video
  • learning summary
  • one activity sheet

Learn

For students looking to achieve grade 4 in GCSE Maths, students must know that a linear equation is drawn as a straight line on a set of axes. A table of values can be used to plot straight line graphs.

Check your understanding of how to draw a graph of a linear equation by watching this short video from BBC Bitesize, KS3 Maths.

Find out how to draw a graph of a linear equation

Read pages 1 to 4 of our 'Straight line graphs' Bitesize revision guide. To understand:

Revise - plotting a straight line graph

How to draw a graph of a linear equation

A linear equation can be represented as a line graph. In order to draw the line graph we require several pairs of coordinates. These coordinates represent the relationship given in the equation.

For example, for y = 3x, the y value is always equal to '3 lots' of the x value. (1,3), (10,30) and (2.5,7.5) are all coordinates on the line y = 3x.

Often a table of values is used to create the coordinates. We use substitution to calculate the values.

For example: y = 2x + 1

The y value is always '2 lots' of the x value plus 1.

We replace the value of x for different numbers and record the resulting y value.

An example of how to plot a straight line graph

Draw the graph of the equation y = 3x - 1.

Create a table of values to find the coordinates on the graph:

Plotting the coordinates and drawing a line through them on a graph looks like this:

This is the graph of y = 3x - 1.

To learn more on how to plot straight line graphs look at the Straight line graphs Bitesize guide here.

Practise

Activity 1

Equations on a straight line

Complete the activity sheet from Beyond on equations on a straight line to test your knowledge.

Equations of a straight line

Choose your exam specification

BBC Bitesize has GCSE exam board-relevant content for students in England, Northern Ireland and Wales. Chose the exam specification that matches the one you study.

Exam board content from BBC Bitesize

There's more to learn...

Have a look at these other resources around the BBC and the web.

Bitesize Daily lessons
GCSE Maths
14 - 16 Maths