Either Works
Part of the Inequalities & Absolute Value section of Coddy's Algebra journey. Lesson 37 of 64.
"x is less than -2 or x is greater than 3" is a different kind of compound inequality. A number is a solution if it satisfies either condition. It does not need to satisfy both. No number is below -2 and above 3 at the same time, so no number could satisfy both. The solutions are two separate rays on the number line, pointing away from each other:
x < -2 or x > 3: two rays, nothing between them
"And" means both conditions must hold, so the solutions are the numbers in both sets. These numbers are called the overlap. "Or" means either condition may hold, so the solutions are the numbers in at least one of the sets. These numbers are called the union. In these examples, the overlap is a segment and the union is two rays. Other pairs of conditions can give other shapes.
An "or" inequality cannot be written as a chain, because a chain means both conditions hold. So x < -2 or x > 3 stays as two inequalities joined by the word "or".
Challenge
MediumShow the solutions of x <= -1 or x > 2 on the number line.
This lesson includes a short quiz. Start the lesson to answer it and track your progress.
This lesson includes a short quiz. Start the lesson to answer it and track your progress.
All lessons in Inequalities & Absolute Value
1What an Inequality Is
The Four SignsA Picture on a LineClosed or OpenReading It BackwardsRecap: What an Inequality Is4Two-Step Inequalities
Two StepsSubtract, Then FlipWith a FractionA Bracket on the WayRecap: Two-Step Inequalities2Adding and Subtracting
Add to Both SidesSubtract from Both SidesNegatives in the MixSolve, Then DrawRecap: Adding and Subtracting5Variables on Both Sides
x on Both SidesGather Toward the LargerBrackets FirstAlways True, Never TrueRecap: Variables on Both Sides11From Words to Inequalities
At Least, At MostMore ThanA Budget That ShrinksTwo LimitsRecap: From Words3Multiplying and Dividing
Divide by a PositiveMultiply by a PositiveThe FlipDividing by a NegativeNegative FractionsRecap: Multiply and Divide6Graphing Solutions
From Inequality to PictureIs the Endpoint In?A Flip on the LineRecap: Graphing Solutions