Linear inequalities are like normal equations, but instead of finding... Show more
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Updated Mar 21, 2026
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Mastering Linear Inequalities
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What are Linear Inequalities?
Think of linear inequalities as equations with attitude - they don't settle for just one answer! Instead of saying x = 3, they might say x > 3, meaning x could be any number greater than 3.
The inequality symbols are your new best mates. Greater than (>) and less than (<) exclude the actual number, whilst greater than or equal to (≥) and less than or equal to (≤) include it. A variable like x represents your unknown number, and the solution set is all the numbers that make your inequality true.
Quick Tip: Remember that > points to the bigger side - if you get confused, think of it as a hungry mouth wanting to eat the larger number!
Solving Linear Inequalities - The Process
Solving inequalities follows the same steps as normal equations: simplify, isolate the variable term, then solve. You can add, subtract, multiply, and divide just like usual equations.
However, there's one massive rule that trips everyone up: when you multiply or divide both sides by a negative number, you must flip the inequality sign. So > becomes <, and ≤ becomes ≥.
Once you've got your solution, you'll often need to show it on a number line. Use an open circle for > and < (the number isn't included) and a closed circle for ≥ and ≤ (the number is included).
Don't Forget: The sign-flipping rule is where most students lose marks - it's the number one exam trap!
Worked Examples - Getting the Hang of It
Let's tackle 3x + 5 < 14. First, subtract 5 from both sides to get 3x < 9. Then divide by 3 (positive number, so no sign flip) to get x < 3. On your number line, use an open circle at 3 with an arrow pointing left.
For the sign-flipping example, try 12 - 2x ≤ 6. Subtract 12 from both sides to get -2x ≤ -6. Now divide by -2 (negative!), so flip the sign: x ≥ 3. Your number line shows a closed circle at 3 pointing right.
Pro Strategy: When solving, pretend it's a normal equation until you hit that negative multiplication or division - then remember to flip!
Variables on Both Sides
When you've got variables on both sides like 7x - 4 > 2x + 11, don't panic! Move all x terms to one side by subtracting 2x from both sides: 5x - 4 > 11.
Add 4 to both sides to get 5x > 15. Finally, divide by 5 (positive number) to get x > 3. Since you divided by a positive, the inequality sign stays the same.
The key is treating it like any other equation - just keep that sign-flipping rule in your back pocket for when you need it.
Remember: Always double-check whether you're multiplying or dividing by a positive or negative number - it makes all the difference!
Number Lines and Visual Solutions
Your number line is like a visual map of your solution. The circle tells you whether the boundary number is included, and the arrow shows which direction contains your solutions.
For open circles (> or <), imagine the number is "off-limits" - you can get infinitely close but never actually reach it. For closed circles (≥ or ≤), the number is part of your solution family.
The arrow direction is logical: if x > 3, then 4, 5, 6 and beyond all work, so your arrow points right towards those larger numbers.
Visual Trick: Think of the arrow as pointing towards all the numbers that would make your inequality true - it's your solution's home!
Exam Success - Key Takeaways
Your exam strategy should focus on the basics: isolate the variable using the same operations on both sides. Know your inequality symbols inside out, and always check if you're multiplying or dividing by a negative.
The biggest exam trap is forgetting to flip the sign when working with negatives. Make this your automatic reflex - negative operation means flip the sign!
For number line questions, remember that open circles go with > and <, whilst closed circles pair with ≥ and ≤. Your arrow direction shows where the solutions live.
Exam Confidence: Master the sign-flipping rule and you've conquered the hardest part - the rest is just like solving regular equations!
We thought you’d never ask...
What is the Knowunity AI companion?
Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.
Where can I download the Knowunity app?
You can download the app from Google Play Store and Apple App Store.
Is Knowunity really free of charge?
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
Most popular content in Mathematics
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4.6/5
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4.7/5
Google Play
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE Knowunity AI. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE Knowunity AI. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
Mastering Linear Inequalities
Linear inequalities are like normal equations, but instead of finding one exact answer, you get a whole range of possible solutions. They use symbols like > and < instead of equals signs, and mastering them is crucial for your maths... Show more
What are Linear Inequalities?
Think of linear inequalities as equations with attitude - they don't settle for just one answer! Instead of saying x = 3, they might say x > 3, meaning x could be any number greater than 3.
The inequality symbols are your new best mates. Greater than (>) and less than (<) exclude the actual number, whilst greater than or equal to (≥) and less than or equal to (≤) include it. A variable like x represents your unknown number, and the solution set is all the numbers that make your inequality true.
Quick Tip: Remember that > points to the bigger side - if you get confused, think of it as a hungry mouth wanting to eat the larger number!
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
Solving Linear Inequalities - The Process
Solving inequalities follows the same steps as normal equations: simplify, isolate the variable term, then solve. You can add, subtract, multiply, and divide just like usual equations.
However, there's one massive rule that trips everyone up: when you multiply or divide both sides by a negative number, you must flip the inequality sign. So > becomes <, and ≤ becomes ≥.
Once you've got your solution, you'll often need to show it on a number line. Use an open circle for > and < (the number isn't included) and a closed circle for ≥ and ≤ (the number is included).
Don't Forget: The sign-flipping rule is where most students lose marks - it's the number one exam trap!
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
Worked Examples - Getting the Hang of It
Let's tackle 3x + 5 < 14. First, subtract 5 from both sides to get 3x < 9. Then divide by 3 (positive number, so no sign flip) to get x < 3. On your number line, use an open circle at 3 with an arrow pointing left.
For the sign-flipping example, try 12 - 2x ≤ 6. Subtract 12 from both sides to get -2x ≤ -6. Now divide by -2 (negative!), so flip the sign: x ≥ 3. Your number line shows a closed circle at 3 pointing right.
Pro Strategy: When solving, pretend it's a normal equation until you hit that negative multiplication or division - then remember to flip!
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
Variables on Both Sides
When you've got variables on both sides like 7x - 4 > 2x + 11, don't panic! Move all x terms to one side by subtracting 2x from both sides: 5x - 4 > 11.
Add 4 to both sides to get 5x > 15. Finally, divide by 5 (positive number) to get x > 3. Since you divided by a positive, the inequality sign stays the same.
The key is treating it like any other equation - just keep that sign-flipping rule in your back pocket for when you need it.
Remember: Always double-check whether you're multiplying or dividing by a positive or negative number - it makes all the difference!
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
Number Lines and Visual Solutions
Your number line is like a visual map of your solution. The circle tells you whether the boundary number is included, and the arrow shows which direction contains your solutions.
For open circles (> or <), imagine the number is "off-limits" - you can get infinitely close but never actually reach it. For closed circles (≥ or ≤), the number is part of your solution family.
The arrow direction is logical: if x > 3, then 4, 5, 6 and beyond all work, so your arrow points right towards those larger numbers.
Visual Trick: Think of the arrow as pointing towards all the numbers that would make your inequality true - it's your solution's home!
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
Exam Success - Key Takeaways
Your exam strategy should focus on the basics: isolate the variable using the same operations on both sides. Know your inequality symbols inside out, and always check if you're multiplying or dividing by a negative.
The biggest exam trap is forgetting to flip the sign when working with negatives. Make this your automatic reflex - negative operation means flip the sign!
For number line questions, remember that open circles go with > and <, whilst closed circles pair with ≥ and ≤. Your arrow direction shows where the solutions live.
Exam Confidence: Master the sign-flipping rule and you've conquered the hardest part - the rest is just like solving regular equations!
We thought you’d never ask...
What is the Knowunity AI companion?
Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.
Where can I download the Knowunity app?
You can download the app from Google Play Store and Apple App Store.
Is Knowunity really free of charge?
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
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Most popular content in Mathematics
Can't find what you're looking for? Explore other subjects.
Students love us — and so will you.
4.6/5
App Store
4.7/5
Google Play
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE Knowunity AI. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE Knowunity AI. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user