solve the equation, x2 - 2x - 8 = 0 by completing the square .

a. x = 4 or x = -2

b. x = 4 or x = 2

c. x = -4 or x = -2

d. x = -4 or x = 2

A

Step-by-step explanation:

Completing the square requires a quadratic in form. Once in this form, calculate .

Here x2 - 2x - 8 = 0 converts to x2 - 2x = 8. So b = -2.

Add 1 to both sides.

x2 - 2x + 1 = 8 + 1

(x -1)^2 = 9

Square root both sides.

x-1 = 3                        x - 1 = -3

x = 4                           x = -2

This is the solution.