Math check
posted by Shawn .
Complete the square: x^2 12x. Which of the following is the correct perfectsquare trinomial?
the answers are:
a.) x^2 +22x+121
b.) x^2 10x+25
c.) x^2 20x+44
d.) x^2 12x+36
This is tough because the answers could be a.) b.) and d.)
I am not sure which to choose.

You are seeing something the rest of us isn't. Only one answer has 12x in it.

To complete the square, you divide the number before the x by 2, square it, and add it to the end. The answer is d.