To find the first four terms of a sequence that starts with 1/2 and has a common difference of 1/3, we can start by adding 1/3 to 1/2 (because it's the common difference). The first term is 1/2 (since it's already given to us). The next term is 1/2 + the common difference, or 1/2 + 1/3 or 5/6. The next term is 5/6 + 1/3, which is 7/6. The next term is 7/6 + 1/3 = 3/2. That means that the first four terms of this sequence are 1/2, 5/6, 7/6, and 3/2.
