Question

Solve the following quadratic by

Answer 1

Answer:

{x  = -1 + √13  ,  x  = -1 - √13}

Step-by-step explanation:

Completing the square:

f(x) = x² + 2x - 12

     = x² + 2x + 1 - 1 - 12

     = (x² + 2x + 1) - 1 - 12

     = (x + 1)² - 13

Solving:

f(x) = 0

⇔ (x + 1)² - 13 = 0

⇔ (x + 1)² = 13

⇔ x + 1 = √13  or  x + 1 = -√13

⇔ x  = -1 + √13  or  x  = -1 - √13