About the Inequality Calculator
Linear, quadratic, and compound inequalities solved with full working.
What it is
The Inequality Calculator solves single-variable linear and quadratic inequalities, along with compound inequalities, showing every algebraic step. It highlights the sign-flip rule whenever both sides are multiplied or divided by a negative number, and reports the solution as an inequality, in interval notation, and on a visual number line.
Features
Sign-flip rule
Explicitly called out whenever multiplying or dividing by a negative number.
Quadratic sign chart
Roots and a sign-chart method combine into the correct solution intervals.
Compound inequalities
Expressions like -3 < 2x + 1 < 5 split, solved, and recombined.
Number line + interval notation
Solution shown visually with open/closed circles and as interval notation.