PLEASE HELP 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

Question

asked Feb 22, 2020 114k views

1 Answer

Hosein Basafa · Answer 1 · 2020-02-27T02:07:47+0000

Answer:

A

Explanation:

Completing the square requires a quadratic in
ax^2+bx=c form. Once in this form, calculate
((b)/(2))^2 .

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

((b)/(2))^2=((-2)/(2))^2=1

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.