 This video, we're going to look at how to use substitution in equations to generate a table of ordered pairs. So ordered pairs can be used to solve equations, to plot graphs, and so we come across them a lot in maths. You should already know how to substitute into equations if you're unsure watch this video first, and how to solve simple equations. And again, if you've forgotten, watch this video. So let's jump straight in. We have this relationship. The value of y depends on what the value of x is. So if x is 2, then y is 7. What if x was 0, 1, or 3? Pause the video and find the corresponding y values. Did you get them right? This table we have generated is known as a table of ordered pairs, or a table of values. It can be horizontal, like this, or vertical. We can then write out the values as ordered pairs. It's really important that we always write the x value before the y value. So 0, 1, not 1, 0. Then 1, 4, and so on. Writing the pairs as x, y is what makes it an ordered pair. The x and the y are both known as variables, because they aren't set values. They vary. Even more specifically, we call the x the independent variable, because we can choose any value of x randomly, or independently. But the y is known as the dependent variable. It depends upon the value of x. So sometimes you might be given a mixture of x and y values, and have to work out the missing values. Pause the video and complete the table of ordered pairs, and then write the outcome as ordered pairs. Did you get them right? Here's the final type of question to try. Which equation represents the values in the table? Pause the video and work it out. Did you get option C? We can then use these ordered pairs and plot them onto a graph, which we'll look at in future videos. If you liked the video, give it a thumbs up, and don't forget to subscribe, comment below if you have any questions. Why not check out our few school app as well? Until next time.