Hello,
Can someone please explain to me how to solve this problem.
Complete the square x^2-8x
I keep looking over the explanation in my book and i just doesn't make sense to me.
Thanks
https://www.youtube.com/watch?v=1BVxDi6W8sI
This video explains the process
You should know that $\displaystyle (x- a)^2= x^2- 2ax+ a^2$. Comparing that to $\displaystyle x^2- 8x$ you can see that "2ax" must be "8x" so that 2a= 8, a= 4. And then $\displaystyle a^2= 4^2= 16$. To make $\displaystyle x^2- 8x$ into the "perfect square" $\displaystyle x^2- 8x+ 16$ we need to add 16- and, of course, in order not to change the value we must also subtract 16: $\displaystyle x^2- 8x+ 16- 16= (x- 4)^2- 16$.