Linear Inequality Solver

Solution
Interval Notation

How It Works

This linear inequality solver uses established formulas to provide accurate results.

The basic rule:

  • ax + b < c → x < (c-b)/a (if a > 0)
  • ax + b < c → x > (c-b)/a (if a < 0, flip inequality)
  • Interval notation: ( ) = open, [ ] = closed

Results are estimates. Consult a professional for critical decisions.

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Frequently Asked Questions

Why do you flip the inequality when dividing by a negative?

Multiplying or dividing both sides of an inequality by a negative number reverses the order. For example, -2 < 3, but multiplying both by -1 gives 2 > -3. The inequality must flip to remain true.

What is interval notation?

Interval notation uses parentheses ( ) for exclusive bounds and brackets [ ] for inclusive bounds. For example, x > 3 is (3, ∞) and x ≤ 5 is (-∞, 5].

What is the difference between < and ≤?

< means strictly less than (does not include the boundary point — open circle on number line). ≤ means less than or equal to (includes the boundary — closed circle).