Question

What value added to x2 − 8x would complete the square?

Answer 1

x^2 - 8x = (x - 4)^2 - 16

we add 16 to give x^2 - 8x + 16 which is a perfect square

x^2 - 8x + 16 = (x - 4)^2

answer is 16

Answer 2

16 is added to complete the square

Explanation:

`x^2-8x`

We use completing the square method to complete the square.

In completing the square method, we take coefficient of x and then divide by 2 and square it

`(-8)/(2) =-4`

`(-4)^2=16`

We add 16 to complete the square

`x^2-8x+16`

`(x-4)(x-4)`

`(x-4)^2`

So, 16 is added to complete the square