In order to solve, we must use the formula:
a1 is the first term, n is the term position, and d is the common difference. We know that the first term is -1, the position we are trying to find is the 12th, and the difference is -6. So plug them all in.
So (12-1) = 11 and 11 (-6) = -66 now subtract 1
Answer is -67