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.