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

Answer:

16 is added to complete the square

Step-by-step 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

$\frac{-8}{2} =-4$

$(-4)^2=16$

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