We really only have to look at these two options here and expand them out. What sum would each of these be? Well this is going to be the same thing as. We're starting at n equals one. So this is going to be three times when n equals one, three times one minus one, and then plus, then we'll go to n equals two, three times two minus one. Then we're gonna go to n equals three, so plus three times three minus one. And then finally we're gonna go to n equals four.