Question

How to show your work of completing the square of x^2-12x+7=0

Answer 1

Example: complete the square of x^2 + 2x + 5.

1) Take half of the coefficient (2) of x. This is 2/2 = 1.
2) Square that quantity 1^2+1.
3) add the result to x^2 + 2x, and then subtract the same thing, and then add that 5:
x^2 + 2x +1 -1 + 5 = x^2 + 2x + 1 +4
4) You'll have a perfect square on the left. Write it as the square of a binomial:
(x+1)^2 + 4.
That's it.

Now please apply this procedure to your homework problem.