If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

Lesson 8: Intro to inequalities with variables

# Testing solutions to inequalities

Inequalities are like puzzles where you compare two things. You can solve these puzzles by trying different numbers and seeing which ones make the puzzle true. Some numbers will work for one puzzle but not for another. It's all about finding the right fit!

## Want to join the conversation?

• is it possible for there to be a negative X?
• yes x can be any value rational or irrational.
• How did he get the numbers 0 1 2 5?
• There is no magic. You can pick any number you want and test it to see if it is a solution to the inequality. Sal just happened to select: 0, 1, 2, and 5.
• I don't under stand this at all
• If you have no trouble solving for regular equations you shouldn't let inequalities scare you away. They may seem confusing but if you learn what the symbols represent and learn to recognize inequalities than you will be fine.

Dont stress it.
Take breaks and if anything repeat what Sal says a loud to yourself. That helps me a lot to understand and listen to what is going on.
• why is it possible for an x to be negative
• yes x can be any number so it could be -1000 if you want it to
• Can you guys help me solve this 2x2+3+4x
• If the x in between the 2's represents multiplication, then this is the answer.

(1.) 2 * 2 + 3 + 4x (Multiplication comes first)
(2.) 4 + 3 + 4x (Now the addition)
(3.) 7 + 4x (This is the final answer because no like terms remain.)
• Sal kinda lost me at the number two... Because he says 2+2 < 2
*2 even tho it would be 4 < 4 which he says is correct but then,when it comes to 3*2+4 > 5*2 which would be 10 > 10 the answer is incorrect-...Why?
• In the first one, the inequality is "less than OR equal to". Since 4=4, the inequality is true.

In the 2nd one, the inequality is "greater than". Since 10 is not greater than 10, it is false.

Hope this helps.
• At don't you have to mutiply 2x2
• Also, the way you have written it out makes it look like two times two, which would equal 4...
• Hi my name is Joel and how do you add the variables.
• Hi Joel,
If you want to add the variables you need to combine 2 coefficients with the same variable.
Ex: 2x + 2x = 4x, 4x - 2x = 2x. These are correct
Ex: 3y + 2x = For this there is no answer cuz they have 2 different variables.

Hope this helps!!
Thank You