Grade 9 math
Lessons commonly taught in grade 9, each with worked examples, practice problems, and complete solutions. Topics often span more than one grade, so you may see a lesson listed under a neighbouring grade too.
9 lessons · 7 standards
Algebra and Equations
- How to Solve Absolute Value Equations
Solve absolute value equations by splitting into two cases, why two answers appear, when there is no solution, and how absolute value inequalities differ.
- Completing the Square, Step by Step
Learn completing the square: why the method works geometrically, how to handle a leading coefficient, and how it produces vertex form and the quadratic formula.
- How to Solve Compound Inequalities (AND and OR)
Solve compound inequalities joined by AND or OR, graph the solution on a number line, and tell which combinations give no solution or every number.
- How to Solve Literal Equations and Rearrange Formulas
Rearrange a formula to solve for any variable using the same inverse operations you use on numbers, with worked examples from geometry, physics, and finance.
- How to Solve Multi-Step Equations
Solve multi-step equations by distributing, combining like terms, then undoing operations in reverse order, with worked examples and practice problems.
- How to Solve Multi-Step Inequalities
Solve multi-step inequalities by distributing, combining like terms, and undoing operations in reverse order, including when to flip the inequality sign.
- The Quadratic Formula: How and Why It Works
Learn the quadratic formula, where it comes from, and how to use it to solve any quadratic equation, with worked examples and practice problems.
- Solving Quadratic Equations by Factoring
Solve quadratics by factoring using the zero product property, why the equation must equal zero first, and how to factor the common trinomial patterns.
- Solving Equations with Variables on Both Sides
Solve equations with variables on both sides by collecting variable terms on one side, plus how to recognise no solution and infinitely many solutions.