This is just, that three n is just zero, so you start at two, and then you keep, every time you increase n by one, you are just adding three again. So finally, when n is equal to three, two plus three times three is two plus, or is 11, I should say. And so this also is exactly the same sum. So I feel good about both of these. Let's do one more example. So we're here, we're given the sum, and we're saying choose one answer. Which of these is equivalent to this sum right over here?