Another solving a quadratic equation by completing the square: Exact answers

Question

Solve the quadratic equation by completing the square.

x^2 - 8x + 2 = 0

First, choose the appropriate form and fill in the blanks with the correct numbers.

Then, solve the equation. If there is more than one solution, separate them with commas.

Answer 1

x^2 - 8x + 2 = 0

x^2 -8x + 16 = - 2 +16

(x-4)^2 = 14

2nd form

(x - blank)^2 = blank:

first blank is 4, 2nd is 14

or if you want to use the 1st form, then

(x + blank)^2 = blank

first blank is -4, 2nd is 14

Answer 2

ax² + bx + c

"Move" c to the other side.

x² - 8x = -2

Take half of b, square it, and add it to both sides. (-4)² = 16

x² - 8x + 16 = 14

Now, that half of b, (- 4), we'll use again.

(x - 4)² = 14