High School · Reasoning with Equations and Inequalities

CCSS.MATH.CONTENT.HSA.REI.B.4b

Solve quadratic equations by inspection (e.g., for x² = 49), taking square roots, completing the square, the quadratic formula and factoring, as appropriate to the initial form of the equation. Recognize when the quadratic formula gives complex solutions and write them as a ± bi for real numbers a and b.

Read this standard on the official Common Core site

Lessons that teach this standard

• 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.