Question

How do you solve `x^2 - 8x - 6=0` using completing the square?

Answer 1

First you change the form into `x^2-8x=6`
(add `6` to both sides)

Explanation:

Method: you halve the `x`-coefficient (`-8`) to get `-4`. The square of this is to be added to both sides.

`->x^2-8x+16=6+16`

`(x-4)^2=22->x-4=+-sqrt22`

`x_(1,2)=4+-sqrt22` (two solutions)
graph{x^2-8x-6 [-52.02, 52.07, -26, 26]}