Hey everyone. I've been having a lot of difficulty in my discrete math class and was hoping you could help me out. I can't seem to figure out how to go about solving problems containing Big-Theta, Big-O and Big-Omega notation. I have a couple of sample questions for what we are doing in my course, and any help with this would be greatly appreciated.

1) n^2 / 3 + 33n is Big-Omega(n)

2) n^3 / 58 - 7n^2 is Big-Theta(n2)

3) 18n^2 - 27n + 47 is Big-O(n3).