Basic Algebra/Solving Quadratic Equations/Solving Quadratic Equations By Taking The Square Root of Both Sides

VocabularyEdit


LessonEdit

One way to solve a quadratic is to use square root. Steps:

  1. Factor a quadratic so that y=(x+z)^2  (z is determined by the quadratic)
  2. Take the square root of both sides, so ±(y^0.5)=x+z
  3. Y is 0, so the square root is zero. Therefore, 0=±(x+y)
  4. Solve for x

Example problemsEdit

  1. 200=2x^2 + 38
  2. 162=2x^2
  3. ±81=x^2
  4. ±9=x


  1. 64=x^2 + 6x + 9
  2. 64=(x+3)^2
  3. 8=x+3
  4. ±5=x