Hello! For this sequence, you are decreasing. In this case, A and C are definitely out, because they are positive, not negative. The formula for sequence is a1 + (n -1)d, where a1 = first term and d = common differnce, The first term is 12 and the common difference is -6. "n" is the order of the sequence and n = 30. 30 - 1 is 29. 29 * -6 is -174. Now, we add 12 to that total and when we add, we subtract the numbers, and then place the negative sign back in. 174 - 12 = 162. Plug in the negative symbol to get -162. There. -162 is the 30th term in the sequence. The answer is D: -162.
