plz help!! test tomorrow!

here is what i need to do_

''Rewrite the following functions in the form y=a(x-h)^2+k.Find the vertex.''

here is my problem_

y = x^2 + 4x - 9

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I tried to learn this but i just can't...my teacher is 2 lazy and not willing to spend any extra time with me. Also not a single stundent in my class knows this stuff. so please HELP! This is my last test and if i dont pass it i will have 2 go to summer school or even worse.

here some more problems_( i know these will be on a test)

y = x^2 - 6x + 16

y = x^2 - 8x - 1

y = x^2 + 5x + 2

thanks