CurriculumGrade 9Mathematics

Equivalent Forms of Expressions

Aligned to A-SSE.B.3 — Common Core State Standards for Mathematics.

What this lesson teaches

Rewriting an expression in a different but equal form can reveal a hidden property — factoring shows the values that make it zero, and factoring out a common factor shows shared structure.

Worked example

Factor x^2 − 5x + 6 to find where it equals zero. It factors as (x − 2)(x − 3), so the expression is 0 when x = 2 or x = 3.

Practice questions

  1. Factor x^2 + 7x + 12 and state where it equals zero.
  2. Factor x^2 − 9 and state where it equals zero.
  3. Rewrite 2x^2 + 8x by factoring out the greatest common factor.

Watch the lesson

Every lesson comes with a video taught in English and Spanish — the same video the QR code in the printed workbook opens.

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En español

Formas Equivalentes de Expresiones

Reescribir una expresión en una forma distinta pero igual puede revelar una propiedad oculta: factorizar muestra los valores que la hacen cero, y sacar un factor común muestra su estructura compartida.

Ejemplo: Factoriza x^2 − 5x + 6 para hallar dónde vale cero. Se factoriza como (x − 2)(x − 3), así que la expresión es 0 cuando x = 2 o x = 3.

More Algebra lessons

Solving Linear Equations and InequalitiesA-REI.B.3Solving Quadratic Equations by FactoringA-REI.B.4Parts of an ExpressionA-SSE.A.1Rewriting by StructureA-SSE.A.2Operations with PolynomialsA-APR.A.1Zeros of PolynomialsA-APR.B.3

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