Lesson video

Hi, I'm Miss Davies.

In this lesson, we're going to be drawing graphs that are in the form axe + by = c.

In which pairs of coordinates is the total of the x and the y value four? , , and.

Which of the points lie on the line x + y is equal to four? These three points lie on this line.

If we complete a table of values for the line x + y is equal to four, we need to make sure that our x and y coordinates add together to make four.

When x is one, y is three.

When x is two, y will also be two.

When x is four, y will be zero.

Next we're going to plot this graph on our grid.

We're going to use these coordinates to plot the points.

And then join these up.

You can see that the gradient of the line is negative one, and both the x and y intercepts are four.

Here are some questions for you to try.

Pause the video to complete your tasks and resume once you're finished.

Here are the answers: your graph should have had a gradient of negative one, and a y intercept of five.

Which coordinates lie on the line 2x + y is equal to four? , , and.

We're going to complete the table of values for the line 2x, add 2y, is equal to six.

We can substitute in the values for x, and then solve the equation to find y.

When x is zero, y is three.

When x is one, y is two.

When x is two, y is one.

When x is three, y is zero.

And when x is four, y is negative one.

We're going to plot this graph using these coordinates that we've just worked out using our table of values.

You can plot all of these points and then join them together.

You can see that the gradient of the line is negative one, and the y intercept is three.

Here are some questions for you to try.

Pause the video to compete your task, and resume once you're finished.

Here are the answers: the equation x + 2y = 10 should have had a gradient of negative a half, and a y intercept of five.

The equation 2x + 2y is equal to 24 should have had a gradient of negative one, and a y intercept of 12.

That's all for this lesson! Thanks for watching!.