Solve the Absolute Value Quadratic: |x²-11|=5

Question

x211=5 |x^2-11|=5

Video Solution

Step-by-Step Solution

To solve the equation x211=5 |x^2 - 11| = 5 , we will consider the two cases implied by the property of absolute values:

  • Case 1: x211=5 x^2 - 11 = 5
  • Case 2: x211=5 x^2 - 11 = -5

Let's solve each case separately.

Case 1: x211=5 x^2 - 11 = 5
First, add 11 to both sides: x2=16 x^2 = 16 .
Taking the square root of both sides, we get x=±16=±4 x = \pm\sqrt{16} = \pm4 .
Thus, the solutions for Case 1 are x=4 x = 4 and x=4 x = -4 .

Case 2: x211=5 x^2 - 11 = -5
First, add 11 to both sides: x2=6 x^2 = 6 .
Taking the square root of both sides, we get x=±6 x = \pm\sqrt{6} .
Thus, the solutions for Case 2 are x=6 x = \sqrt{6} and x=6 x = -\sqrt{6} .

Therefore, combining solutions from both cases, the complete set of solutions is x=4,4,6,6 x = 4, -4, \sqrt{6}, -\sqrt{6} .

Reviewing the multiple-choice options, both cases' solutions correspond to the correct answer listed as 'Answers a + b.'

Answer

Answers a + b