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Linear Inequality Calculator

Solve any linear inequality instantly — get step-by-step solutions, number line graphs, and interval notation. Free, no sign-up required.

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Why this page ranks for linear intent

Focused on linear one-variable inequalities and linear two-variable graphing.
Explains the sign-flip rule instead of hiding it behind a paywall or login.
Pairs every answer with steps, number-line meaning, interval notation, and verification.

Linear Solver

Built for one-variable linear inequalities with instant steps, a number line, interval notation, and linear two-variable graphing when your input includes y.

Live parse preview
2x + 3 > 7

Supported Input Styles

  • 2x+3>7 becomes a linear one-variable inequality.
  • 5-x<=2 keeps the negative coefficient logic visible.
  • 3(x+1)>=-8 expands parentheses before solving.
  • x/2+3>1 treats the fraction as part of the linear expression.
  • 2x+3y<6 switches to coordinate-plane graphing automatically.

Math Keyboard

Tap symbols, numbers, or actions for fast linear-inequality input.

Result

The linear inequality isolates x > 2.

Solution2x+3 > 7
Interval(2, ∞)
1

Step 1

Move all terms to one side

Rewrite the inequality so the right-hand side is zero.

Before

2x+3>72x+3 > 7

After

2x4>02x - 4 > 0
2

Step 2

Isolate x

Add or subtract the constant term so that the x-term stands alone.

Before

2x4>02x - 4 > 0

After

2x>42x > 4
3

Step 3

Divide by the coefficient of x

Dividing both sides by a positive number keeps the inequality direction the same.

Before

2x>42x > 4

After

x>2x > 2
Use the tabs to move between the algebra, graph, notation, and verification views.

Recent History

Saved locally in this browser so you can jump back into recent linear problems without any backend.

Solve a few linear inequalities and the latest ones will appear here.

Calculator Types

Switch to another inequality tool in one tap

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How to Use the Linear Inequality Calculator

The fastest way to use the linear inequality calculator is to type the inequality exactly as you would write it in class. You can enter forms such as 2x + 3 > 7, 5 - x <= 2, 3(x + 2) >= 12, or x/2 - 3 > 1. The parser accepts common keyboard input, so you do not need special math markup just to get started.

After you enter a problem, the page keeps the result area tightly focused on the four views that matter most for linear work: algebraic steps, the graph, interval notation, and verification. That structure is intentional. Many calculator pages stop after they isolate x, but students usually need one more layer of interpretation. They want to know what the answer means on a number line and whether a test value really works.

If you are checking homework, begin with the Steps tab and compare each transformation to your own work. If you are learning the topic for the first time, switch to the Graph and Interval Notation tabs right after that. Seeing the algebra and the visual answer together is the quickest way to understand why x > 2 becomes an open endpoint with shading to the right, while x <= 5 becomes a closed endpoint with shading to the left.

01

Enter a linear inequality such as 2x + 3 > 7, 5 - x <= 2, or 2x + 3y < 6.

02

Review the step cards to see how the variable is isolated and when the inequality sign stays the same or flips.

03

Open the graph, interval notation, and verify tabs to confirm the answer from several angles.

What Is a Linear Inequality?

A linear inequality compares two first-degree expressions. Instead of asking when two expressions are equal, it asks when one side is greater than, less than, or equal to the other in an inequality sense. That is why a problem like 2x + 3 > 7 usually has many correct values. Every real number larger than 2 works, so the answer is a set of values, not a single solution.

This is the key distinction between a linear equation and a linear inequality. An equation such as 2x + 3 = 7 has one exact answer, x = 2. The related inequality 2x + 3 > 7 has an entire ray of answers, x > 2. The variable still has degree one, the algebra rules are still familiar, but the final interpretation is different because the result describes a range.

You will most often see four symbols in linear inequality work: >, <, >=, and <=. Strict symbols, > and <, exclude the boundary value. Inclusive symbols, >= and <=, include the boundary value. That inclusion rule shows up everywhere: in the final isolated statement, in interval notation, and on the graph where the endpoint changes from an open circle to a closed circle.

Equation example

2x+3=72x + 3 = 7

Inequality example

2x+3>72x + 3 > 7
Comparison pointLinear equationLinear inequality
GoalFind the exact value that makes both sides equal.Find every value that keeps the comparison true.
Typical answerA single value such as x = 2.A range such as x > 2 or -1 <= x < 4.
GraphOne point on a number line.A shaded ray or interval.
NotationUsually a single algebraic statement.Often written in inequality, interval, and set notation.

How to Solve Linear Inequalities Step by Step

The algebra behind linear inequalities is familiar on purpose: combine like terms, isolate the variable, and read the final statement carefully. The difference is in interpretation. Every move must preserve the truth of the comparison, and one rule matters more than any other rule on the page: dividing by a negative number reverses the inequality symbol.

Add or subtract the same number on both sides

Adding or subtracting the same value keeps the balance of the comparison. The inequality direction does not change because you are shifting both sides by the same amount.

Example

2x+3>7    2x>42x + 3 > 7 \;\Rightarrow\; 2x > 4

Multiply or divide by a positive number

When the number is positive, the order of values stays the same. Dividing 6 > 2 by 2 gives 3 > 1, so the inequality symbol remains unchanged.

Example

2x>4    x>22x > 4 \;\Rightarrow\; x > 2

Multiply or divide by a negative number

This is the most common source of mistakes. Negative multiplication reverses order, so the symbol must flip direction. If -4x < 8, then x > -2 after dividing by -4.

Example

4x<8    x>2-4x < 8 \;\Rightarrow\; x > -2
Dividing by a negative number reverses the inequality sign. If you forget that flip, the final answer is wrong even if the algebra around it looks clean.

Move variable terms to one side

If x appears on both sides, gather the variable terms first. This makes the structure easier to read and reveals whether the remaining coefficient of x is positive or negative.

Example

2x+13x4    1x42x + 1 \ge 3x - 4 \;\Rightarrow\; 1 \ge x - 4

Expand parentheses before isolating the variable

A distributed form is much easier to solve correctly. Expand, combine like terms, then continue with the usual add, subtract, multiply, or divide steps.

Example

3(x+2)12    3x+6123(x + 2) \ge 12 \;\Rightarrow\; 3x + 6 \ge 12

Forgetting to reverse the sign

If you divide by a negative coefficient and keep the original symbol, you reverse the meaning of the answer. Always pause before the last step when the coefficient of x is negative.

Mixing up open and closed endpoints

Strict inequalities use open circles and parentheses. Inclusive inequalities use closed circles and brackets. Matching these consistently keeps the graph and interval notation aligned.

Making sign errors while moving terms

Students often change +3 into +3 again instead of -3 when moving it across the inequality. The cleaner habit is to add or subtract the same value on both sides rather than relying on an informal move-term shortcut.

Expanding parentheses incorrectly

A missed negative sign during distribution can break the whole solution. Expand slowly, then combine like terms before you isolate the variable.

Linear Inequality Examples

The six examples below were chosen to cover the most common classroom patterns: basic isolation, a negative coefficient, parentheses, a forced sign flip, fractions, and variables on both sides. If you can explain why each final graph looks the way it does, you understand the topic at a usable level.

Example 1Basic linear form
2x+3>72x + 3 > 7

This is the simplest linear-inequality pattern. The variable is already on one side, so you only need one subtraction step and one division step.

1

Subtract 3 from both sides

Before

2x+33>732x + 3 - 3 > 7 - 3

After

2x>42x > 4
2

Divide both sides by 2

Before

2x2>42\frac{2x}{2} > \frac{4}{2}

After

x>2x > 2

Answer

x>2x > 2

Interval

(2,)(2, \infty)

Set notation

{xx>2}\{ x \mid x > 2 \}

Number line

Example 2Negative variable coefficient
5x25 - x \le 2

This example teaches an important idea: the sign does not flip when you subtract 5, but it does flip when you divide by -1.

1

Subtract 5 from both sides

Before

5x5255 - x - 5 \le 2 - 5

After

x3-x \le -3
2

Divide both sides by -1

Before

x131\frac{-x}{-1} \ge \frac{-3}{-1}

After

x3x \ge 3
Dividing by -1 reverses the inequality sign.

Answer

x3x \ge 3

Interval

[3,)[3, \infty)

Set notation

{xx3}\{ x \mid x \ge 3 \}

Number line

Example 3Parentheses and distribution
3(x+2)123(x + 2) \ge 12

Parentheses hide the linear structure. Once you distribute, the inequality becomes a familiar two-step problem.

1

Distribute the 3

Before

3(x+2)123(x + 2) \ge 12

After

3x+6123x + 6 \ge 12
2

Subtract 6 from both sides

Before

3x+661263x + 6 - 6 \ge 12 - 6

After

3x63x \ge 6
3

Divide both sides by 3

Before

3x363\frac{3x}{3} \ge \frac{6}{3}

After

x2x \ge 2

Answer

x2x \ge 2

Interval

[2,)[2, \infty)

Set notation

{xx2}\{ x \mid x \ge 2 \}

Number line

Example 4Sign flip with a negative coefficient
4x+1<9-4x + 1 < 9

This example is a classic check for sign-flip discipline. The final step is simple, but it is also where most errors happen.

1

Subtract 1 from both sides

Before

4x+11<91-4x + 1 - 1 < 9 - 1

After

4x<8-4x < 8
2

Divide both sides by -4

Before

4x4>84\frac{-4x}{-4} > \frac{8}{-4}

After

x>2x > -2
Dividing by a negative number reverses the inequality sign.

Answer

x>2x > -2

Interval

(2,)(-2, \infty)

Set notation

{xx>2}\{ x \mid x > -2 \}

Number line

Example 5Fractional coefficient
x23>1\frac{x}{2} - 3 > 1

Fractions are easier when you isolate the fractional term first. Because you multiply by a positive number, the sign stays exactly the same.

1

Add 3 to both sides

Before

x23+3>1+3\frac{x}{2} - 3 + 3 > 1 + 3

After

x2>4\frac{x}{2} > 4
2

Multiply both sides by 2

Before

2x2>242 \cdot \frac{x}{2} > 2 \cdot 4

After

x>8x > 8

Answer

x>8x > 8

Interval

(8,)(8, \infty)

Set notation

{xx>8}\{ x \mid x > 8 \}

Number line

Example 6Variables on both sides
2x+13x42x + 1 \ge 3x - 4

When x appears on both sides, your first goal is to collect the variable terms into one place. Only then can you see the final direction of the answer.

1

Subtract 2x from both sides

Before

2x+12x3x42x2x + 1 - 2x \ge 3x - 4 - 2x

After

1x41 \ge x - 4
2

Add 4 to both sides

Before

1+4x4+41 + 4 \ge x - 4 + 4

After

5x5 \ge x
3

Rewrite in standard variable-first form

Before

5x5 \ge x

After

x5x \le 5

Answer

x5x \le 5

Interval

(,5](-\infty, 5]

Set notation

{xx5}\{ x \mid x \le 5 \}

Number line

Linear Inequalities on a Number Line

A number line translates algebra into a picture. Once you isolate x, the graph answers two quick questions: where is the boundary, and which side should be shaded? For x > 2, the boundary is 2 and the shading extends to the right because larger values satisfy the inequality. For x < 2, the boundary is still 2, but the shading moves left because smaller values work instead.

The endpoint style matters just as much as the direction. Open circles match strict symbols, > and <, because the boundary itself does not belong to the solution. Closed circles match inclusive symbols, >= and <=, because the endpoint is part of the answer. If you can read a number line correctly, interval notation becomes much more intuitive because you can see why (2, infinity) excludes 2 while [2, infinity) includes it.

Strict inequality

Use an open circle when the endpoint is excluded, as in x > 2 or x < -1.

Inclusive inequality

Use a closed circle when the endpoint is included, as in x >= 2 or x <= -1.

Interval Notation for Linear Inequalities

Interval notation is the compact form of a graph. Parentheses mean an endpoint is excluded, and brackets mean an endpoint is included. Infinity is never written with a bracket because infinity is not a reachable endpoint on the real line.

A good habit is to read interval notation out loud. For example, [3, infinity) means every real number from 3 upward, with 3 included. That verbal check helps you catch mistakes before you turn in homework or copy the final answer into another system.

InequalityInterval notationNumber lineMeaning
x>ax > a
(a,)(a, \infty)
Values greater than a, but not including a.
xax \ge a
[a,)[a, \infty)
Values greater than a, including a.
x<ax < a
(,a)(-\infty, a)
Values less than a, but not including a.
xax \le a
(,a](-\infty, a]
Values less than a, including a.

Frequently Asked Questions

What is a linear inequality?

A linear inequality is a comparison that uses a first-degree expression, such as 2x + 3 > 7 or 5 - x <= 2. Its solution is usually a range of values, not one single number.

What is the difference between a linear equation and a linear inequality?

A linear equation asks for the exact value that makes two sides equal, while a linear inequality asks for every value that makes one side greater than, less than, greater than or equal to, or less than or equal to the other.

What are the four inequality symbols?

The four core inequality symbols are >, <, >=, and <=. They mean greater than, less than, greater than or equal to, and less than or equal to.

What does the solution of a linear inequality represent?

The solution represents every real number that makes the original statement true. That is why answers are often written as intervals, rays, or shaded regions instead of a single point.

How do you solve a linear inequality step by step?

Simplify both sides, move variable terms to one side, move constants to the other, and divide by the coefficient of the variable. If that coefficient is negative, reverse the inequality symbol.

When do you flip the inequality sign?

You flip the inequality sign only when you multiply or divide both sides by a negative number. Adding or subtracting values does not reverse the inequality.

How do you solve a linear inequality with variables on both sides?

Collect all x-terms on one side and all constant terms on the other side first. Once the inequality is rewritten as ax > b or ax <= b, divide by a and flip the sign only if a is negative.

How do you solve a linear inequality with fractions?

Clear the fraction carefully or isolate the fractional term first. As long as you multiply or divide by a positive number, the inequality sign stays the same.

How do you solve a linear inequality with parentheses?

Distribute first so the expression is fully expanded. After that, combine like terms and solve as a standard linear inequality.

Can a linear inequality have no solution?

Yes. If the variable terms cancel and the remaining statement is false, such as 4 < 1, then no real number satisfies the inequality.

Can a linear inequality have all real numbers as solution?

Yes. If the variable terms cancel and the remaining statement is always true, such as 2 <= 5, then every real number is a solution.

How do you write the solution in interval notation?

Use parentheses for strict inequalities and brackets for inclusive inequalities. For example, x > 2 becomes (2, infinity), while x >= 2 becomes [2, infinity).

How do you graph a linear inequality on a number line?

Plot the boundary value first, draw an open or closed circle depending on whether the endpoint is excluded or included, and shade left or right depending on the direction of the inequality.

What is the difference between open and closed circles on a number line?

An open circle means the endpoint is not included, so it is used with < or >. A closed circle means the endpoint is included, so it is used with <= or >=.

How do you write the solution in set notation?

Set notation describes the rule directly, such as {x | x > -3}. It tells you which values of x belong to the solution set.

How do I use this linear inequality calculator?

Type a linear inequality into the input, tap Solve or press Enter, and then switch between the steps, graph, interval notation, and verify tabs. Example buttons are included if you want to start with a model problem.

Does this calculator show steps?

Yes. The calculator explains each main algebra move, highlights the final isolated statement, and calls out the sign-flip rule when a negative coefficient is involved.

Can this calculator solve two-variable linear inequalities?

Yes. If your input contains y, the calculator switches from number-line mode to coordinate-plane mode and shades the correct half-plane.

Is this linear inequality calculator free?

Yes. The calculator, graph, interval notation, and explanation content are available without a sign-up.

What types of inequalities can this calculator solve?

This page is optimized for linear inequalities, including expressions with parentheses, fractions, variables on both sides, and linear two-variable inequalities for graphing.

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Related calculators for the next step

Once you are comfortable with linear inequalities, the next useful jumps are compound inequalities, absolute-value inequalities, and graphing-focused practice. Those pages extend the same algebra rules into new answer shapes and new visual interpretations.