Think about this:
is the same thing.
is also the same thing.
So what you need to figure out is what number added to itself makes -6. That is: and if you square it what number do you get? .
What ever that ? is you need to make the -8 in your equation equal that by adding and subtracting the some number to it. and splitting it up like above.
Okay, so -6(x+x=-6) x=1/2 for -6 to = -6 right? square it and you get 1/4.
So I need to make 1/4 = to -8? Man im confused. I know I've done this before I just forgot how to do it!
You've got it exactly. My original post was spaced badly. I corrected. Your method you just did is essentially the same as what I described.
So now from your earlier formula
a=1, h=3, and k=-17. Fill that in with whatever you were working on.