Eliminating a variable

In this lesson, we will determine how to eliminate a variable by adding or subtracting one equation to or from the other.

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Quiz:

Intro quiz - Recap from previous lesson

Before we start this lesson, let’s see what you can remember from this topic. Here’s a quick quiz!

Q1.If x=3 and 2x+5y=41, what is the value of y?

1/5

Q2.7x+2y=24 AND 4x+2y=18. Find the value of 3x

2/5

Q3.7x+2y=24 AND 4x + 2y = 18. Find the value of y

3/5

Q4.9x +6y=168 AND 9x +4y=160. Solve

4/5

Q5.4x +8y=116 AND 4x +4y=68. Solve

5/5

This quiz includes images that don't have any alt text - please contact your teacher who should be able to help you with an audio description.

Unit quizzes are being retired in August 2023

Why we're removing unit quizzes from the website >
Quiz:

Intro quiz - Recap from previous lesson

Before we start this lesson, let’s see what you can remember from this topic. Here’s a quick quiz!

Q1.If x=3 and 2x+5y=41, what is the value of y?

1/5

Q2.7x+2y=24 AND 4x+2y=18. Find the value of 3x

2/5

Q3.7x+2y=24 AND 4x + 2y = 18. Find the value of y

3/5

Q4.9x +6y=168 AND 9x +4y=160. Solve

4/5

Q5.4x +8y=116 AND 4x +4y=68. Solve

5/5

Video

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Worksheet

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This quiz includes images that don't have any alt text - please contact your teacher who should be able to help you with an audio description.

Unit quizzes are being retired in August 2023

Why we're removing unit quizzes from the website >
Quiz:

Eliminating a variable: add or subtract?

Don’t worry if you get a question wrong! Forgetting is an important step in learning. We will recap next lesson.

Q1.3x+2y=5 AND 3x-2y=7. If I add these two equations together, which unknown will be eliminated?

1/5

Q2.3x+2y=5 AND 3x-2y=7. If I subtract the two equations, which unknown will be eliminated?

2/5

Q3.3x-5y=17 AND 2x-5y=10. Subtract the first equation from the second equation.

3/5

Q4.2x-5y=10 AND 3x-5y=17. Add the two equations together.

4/5

Q5.3x-5y=17 AND 7x-5y=20. How can I eliminate y from these simultaneous equations?

5/5

This quiz includes images that don't have any alt text - please contact your teacher who should be able to help you with an audio description.

Unit quizzes are being retired in August 2023

Why we're removing unit quizzes from the website >
Quiz:

Eliminating a variable: add or subtract?

Don’t worry if you get a question wrong! Forgetting is an important step in learning. We will recap next lesson.

Q1.3x+2y=5 AND 3x-2y=7. If I add these two equations together, which unknown will be eliminated?

1/5

Q2.3x+2y=5 AND 3x-2y=7. If I subtract the two equations, which unknown will be eliminated?

2/5

Q3.3x-5y=17 AND 2x-5y=10. Subtract the first equation from the second equation.

3/5

Q4.2x-5y=10 AND 3x-5y=17. Add the two equations together.

4/5

Q5.3x-5y=17 AND 7x-5y=20. How can I eliminate y from these simultaneous equations?

5/5

Lesson summary: Eliminating a variable

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