SOLUTION: I am not able to figure this one out, the question is as follows: What number would you add to the equation below to complete the square? x^2 - 13x=0 A. 26 B. 169/4 C. 13/

Algebra ->  Square-cubic-other-roots -> SOLUTION: I am not able to figure this one out, the question is as follows: What number would you add to the equation below to complete the square? x^2 - 13x=0 A. 26 B. 169/4 C. 13/      Log On


   



Question 463724: I am not able to figure this one out, the question is as follows:
What number would you add to the equation below to complete the square?
x^2 - 13x=0
A. 26
B. 169/4
C. 13/4
D. 169/2
I have tried replacing x with all of these numbers and to no avail. It has been over 15 years since I have taken an algebra class! Please help me understand what I am overlooking.

Answer by robertb(5830) About Me  (Show Source):
You can put this solution on YOUR website!
Whatever the coefficient of the x term is (not the x%5E2 term!), divide by 2, and then square the result. In this case, the coefficient of x is -13. Dividing by 2 and then squaring, we get %28%28-13%29%2F2%29%5E2+=+169%2F4.