Free Algebra Guide

Multi-Step Inequalities

Learn how to solve multi-step inequalities using distribution, combining like terms, inverse operations, variables on both sides, fractions, and the special rule for multiplying or dividing by negative numbers.

Multi-step inequalities combine several algebra skills in one problem. Before isolating the variable, you may need to distribute, combine like terms, simplify both sides, or move variable terms. After simplifying, solve with inverse operations. Remember that the inequality symbol reverses only when you multiply or divide both sides by a negative number.

Several Algebra Steps

What Is a Multi-Step Inequality?

A multi-step inequality requires several algebra steps before the variable is isolated. The problem may contain parentheses, multiple variable terms, constants that can be combined, or variables on both sides.

3(x + 4) + 2x < 27
Parentheses appear first.
Use the distributive property.
Like terms remain afterward.
Combine the x-terms.
Then solve the simplified inequality.
Undo the constant and coefficient.
3(x + 4) + 2x < 27 → 3x + 12 + 2x < 27 → 5x + 12 < 27 → 5x < 15 → x < 3

Simplify Before You Solve

Why Simplification Comes First

Trying to isolate the variable before simplifying often creates unnecessary work. First simplify each side of the inequality as much as possible.

Simplify

Expression Work

Distribute and combine like terms before using inverse operations.

Solve

Inequality Work

Once simplified, use inverse operations to isolate the variable.

Simplifying Does Not Reverse the Inequality

Distributing or combining like terms does not automatically change the inequality direction. The symbol reverses only when both sides are multiplied or divided by a negative number.

Remove Parentheses

Using the Distributive Property

Multiply the factor outside the parentheses by every term inside. Keep the inequality symbol unchanged during the simplification.

Example: 3(x + 4) + 2x < 27

Start
3(x + 4) + 2x < 27
Distribute 3
3x + 12 + 2x < 27

Multiply Every Term Inside

3(x + 4) becomes 3x + 12, not 3x + 4.

Simplify Matching Terms

Combining Like Terms

After distribution, combine terms with identical variable parts. Constants can also be combined with other constants.

Current inequality
3x + 12 + 2x < 27
Combine x-terms
5x + 12 < 27

Keep Unlike Terms Separate

5x and 12 cannot be combined because one is a variable term and the other is a constant.

Gather the Variable Terms

Inequalities With Variables on Both Sides

If variable terms appear on both sides, use addition or subtraction to move them to one side before finishing the solution.

Example: 5x + 4 < 2x + 19

Subtract 2x
3x + 4 < 19
Subtract 4
3x < 15
Divide by 3
x < 5

Addition and Subtraction Do Not Flip the Sign

Moving a variable term by adding or subtracting the same term on both sides does not reverse the inequality.

Solve After Simplifying

Using Inverse Operations

Once the inequality is simplified, remove the constant and then undo the coefficient or divisor.

Current Inequality Next Step Result
5x + 12 < 27 Subtract 12 5x < 15
5x < 15 Divide by 5 x < 3
−3x < 12 Divide by −3 x > −4
x/4 ≥ 6 Multiply by 4 x ≥ 24

The Critical Inequality Rule

When Do You Reverse the Inequality Sign?

Reverse the inequality symbol only when you multiply or divide both sides by a negative number.

Example: 2x − 5x + 4 < 16

Combine x-terms
−3x + 4 < 16
Subtract 4
−3x < 12
Divide by −3
x > −4

Notice When the Flip Happens

Combining like terms did not reverse the symbol. Subtracting 4 did not reverse the symbol. Only the final division by −3 changed < to >.

Multiply or divide by a negative → reverse < and >, or reverse ≤ and ≥.

Rational Coefficients and Solutions

Multi-Step Inequalities With Fractions

Fractional coefficients follow the same process. Simplify the fractional terms first, then use inverse operations.

Example: 1 2 x + 3 2 x + 4 < 16

Combine like terms
2x + 4 < 16
Subtract 4
2x < 12
Divide by 2
x < 6

Negative Fraction Example

−1/2x < 4 → x > −8

Multiplying both sides by −2 reverses the inequality.

Show the Solution Set

Graphing Multi-Step Inequality Solutions

After completing all algebra steps, graph the final inequality on a number line.

Final Solution Endpoint Shade
x < 3 Open circle at 3 Left
x > −4 Open circle at −4 Right
x ≤ 5 Closed circle at 5 Left
x ≥ −2 Closed circle at −2 Right

Open vs. Closed Circles

Use an open circle for < or >. Use a closed circle for ≤ or ≥ because the endpoint is included.

Test a Value

How to Check a Multi-Step Inequality Solution

Choose a value from the solution set and substitute it into the original inequality.

Check x < 3 in 3(x + 4) + 2x < 27

Choose x = 2 because 2 is less than 3.

3(2 + 4) + 2(2) < 27
18 + 4 < 27, so 22 < 27 is true.

Apply the Full Process

Worked Multi-Step Inequality Examples

Combine Like Terms

3x + 2x + 4 < 24

  1. Combine: 5x + 4 < 24.
  2. Subtract 4: 5x < 20.
  3. Divide by 5: x < 4.
Distribution

4(x − 2) + x ≤ 17

  1. Distribute: 4x − 8 + x ≤ 17.
  2. Combine: 5x − 8 ≤ 17.
  3. Add 8, then divide by 5: x ≤ 5.
Negative Final Coefficient

2x − 5x + 4 < 16

  1. Combine: −3x + 4 < 16.
  2. Subtract 4: −3x < 12.
  3. Divide by −3 and reverse: x > −4.
Negative Distribution

−4(x − 2) + 2x ≤ 18

  1. Distribute: −4x + 8 + 2x ≤ 18.
  2. Combine: −2x + 8 ≤ 18.
  3. Subtract 8: −2x ≤ 10.
  4. Divide by −2 and reverse: x ≥ −5.
Variables on Both Sides

5x + 4 < 2x + 19

  1. Subtract 2x: 3x + 4 < 19.
  2. Subtract 4: 3x < 15.
  3. Divide by 3: x < 5.
Fractional Coefficient

−3/4x + 1/4x + 2 < 6

  1. Combine: −1/2x + 2 < 6.
  2. Subtract 2: −1/2x < 4.
  3. Multiply by −2 and reverse: x > −8.
Fractional Distribution

1/2(4x + 6) + x > 12

  1. Distribute: 2x + 3 + x > 12.
  2. Combine: 3x + 3 > 12.
  3. Subtract 3: 3x > 9.
  4. Divide by 3: x > 3.
Two Distributive Groups

2(x + 3) + 3(x + 4) < 28

  1. Distribute: 2x + 6 + 3x + 12 < 28.
  2. Combine: 5x + 18 < 28.
  3. Subtract 18: 5x < 10.
  4. Divide by 5: x < 2.

Watch for These Errors

Common Mistakes With Multi-Step Inequalities

Solving Before Simplifying

Distribute and combine like terms before trying to isolate the variable.

Distributing to Only One Term

The outside factor must multiply every term inside the parentheses.

Combining Unlike Terms

Variable terms and constants cannot be combined unless their variable parts match.

Flipping the Sign During Addition or Subtraction

Adding or subtracting the same value on both sides does not reverse the inequality.

Forgetting the Negative Sign Flip

If you multiply or divide both sides by a negative number, the inequality symbol must reverse.

Losing a Negative During Distribution

Carefully multiply every term when the factor outside the parentheses is negative.

Skipping Algebra Steps

Write one complete updated inequality at a time so errors are easier to identify.

A Reliable Process

Steps for Solving Multi-Step Inequalities

1. Distribute if needed
Remove parentheses by multiplying the outside factor by every term inside.
2. Combine like terms
Simplify matching variable terms and constants on each side.
3. Move variable terms if needed
If variables appear on both sides, use addition or subtraction to gather them on one side.
4. Remove the constant
Use addition or subtraction on both sides.
5. Remove the coefficient or divisor
Use multiplication, division, or a reciprocal to isolate the variable.
6. Check whether the symbol must reverse
Reverse the inequality only if you multiplied or divided by a negative number.
7. Graph the solution
Use an open or closed endpoint and shade in the correct direction.
8. Check a value
Substitute a value from the solution set into the original inequality.
Simplify first. Solve second. Reverse only for negative multiplication or division.

Practice Solving Multi-Step Inequalities

Open the interactive inequalities tool and choose Multi-Step to practice distribution, like terms, negative coefficients, fractions, and inequality sign reversals one algebra step at a time.

Open the Solving Inequalities Tool

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