Inequalities are like equations but with <, >, ≤, ≥ instead of =. Solve them the same way as equations, with one crucial difference: multiplying or dividing by a negative number FLIPS the inequality sign. The solution is a range of values, not a single point.
How to Use
Enter an inequality:
- Coefficients: ax + b ◻ c
- Operator: <, >, ≤, ≥
- Solution: x ◻ value + interval
The Sign Flip Rule
When you multiply or divide both sides by a negative number, the inequality REVERSES. Example: −2x > 6 → x < −3 (not x > −3). This is the most common mistake in inequality solving.
Interval Notation
- x > 3: (3, ∞)
- x ≤ 5: (−∞, 5]
- Parenthesis () = excludes endpoint
- Bracket [] = includes endpoint
Step-by-Step Instructions
- 1Enter coefficient a.
- 2Enter constant b.
- 3Select the inequality operator.
- 4Enter the right-hand side c.
- 5View the solution and number line.