complete the square: y=x^2-6x+7
I am not certain of what you are bieing asked to do but this is what I would assume
subtract 7 off both sides
y-7 = x^2-6x
The x co-efficient is -6
(-6/2) 2 = 3 2 = 9
add 9 to both sides
y-7+9 = x^2 - 6x +9
y+2 = (x-3) 2
