Lesson video

Hello, my name is Miss Parnham.

In this lesson, we're going to learn how to solve two step equations.

Let's solve this equation.

We need to eliminate the constant value first.

So we add 11 to both sides of the equation.

Now 35 equals 5g.

Then we can isolate g by dividing both sides by five.

So seven equals g, or if you prefer g equals seven.

Here, we have a word problem.

I think of a number, multiply it by six, then divide by five, and the answer is negative 12.

To form an equation, we have 6h divided by five equals negative 12.

Let's multiply both sides by five.

So 6h is negative 60, and then divide both sides by six.

So h is equal to negative 10.

Here are some questions for you to try.

Pause the video to complete the task, and restart the video when you're finished.

Here are the answers.

In question two, we have an isosceles triangle with two equal angles, and that's why they're both labelled t.

All triangles have an angle sum of 180 degrees.

So when we've found the equation, we have 2t plus 104 equals 180, and we solve to find t equals 38.

Here are some further questions for you to try.

Pause the video to complete the task, and restart the video when you're finished.

Here are the answers.

We can solve equations involving decimals in just the same way as those that contain integers.

So let's subtract 3.

1 from both sides of this equation.

So 6m equals 10.

8.

Dividing by six, m equals 1.

8.

For this equation a function machine can help us apply inverses in the correct order.

So the secret equation means that n has been divided by two, then 4.

3 has been subtracted to give the answer negative 5.

45.

Let's reverse the process.

So starting at negative 5.

45, let's add 4.

3.

That gets us negative 1.

15.

Let's multiply by two.

So n is negative 2.

3.

Here are some questions for you to try.

Pause the video to complete the task, and restart the video when you're finished.

Here are the answers.

If you have answers which are equivalent fractions or decimals to these, then of course you can mark them correct too.

Here are some further questions for you to try.

Pause the video to complete the task, and restart the video when you're finished.

Here are the answers.

You will probably recall that the mean is found by finding the sum of a set of numbers, then dividing by how many there are.

So if you know the mean and you multiply by how many values there are, then you can find the total.

In question eight, you have the option that both mystery numbers are the same.

So you may have written 2c plus negative 2.

4 equals 3.

3 and solved to find 2.

85.

The other option is one of the mystery cards could be the same as negative 2.

4, and the other one different.

So c plus negative 4.

8 equals 3.

3.

In which case, c would be 8.

1.

That's all for this lesson.

Thanks for watching.