Greater Than: Outside
Part of the Inequalities & Absolute Value section of Coddy's Algebra journey. Lesson 50 of 64.
The inequality |x| > 3 asks for the numbers more than three steps from zero, in either direction. Those are the numbers above 3 and the numbers below -3. The answer has two separate pieces, joined by "or":
x > 3
or
x < -3
|x| > 3: more than three steps from zero, on either side
When an absolute value is greater than a number, it splits into two cases: |u| > c becomes u > c or u < -c. Look at the second case. A number far below zero is less than -c, so the sign turns around with the minus. "Less than" gives a chain, the numbers between. "Greater than" gives an "or", the numbers outside. Draw each one on a number line to remember which is which.
Challenge
MediumSolve the inequality |x| >= 2 for x.
Try it yourself
Solve for x
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 Inequalities7Between Two Numbers
Two Conditions at OnceSolving a ChainTwo Moves on All PartsWhen the Chain FlipsChains with FractionsRecap: Between Two Numbers10Absolute Value Inequalities
Less Than: BetweenBetween, ShiftedGreater Than: OutsideOutside, ShiftedIsolate, Then SplitAlways or NeverRecap: Absolute 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