You can put this solution on YOUR website! We know that it is an arithmetic sequence with common difference -6. So, somewhere in the general expression there would have to be a -6n, and since it is arithmetic the only possible expression is some constant coupled with the -6n, so the general expression is
The first term (n=1) is 64, so we can solve for C and get C = 70. Hence, the nth term is given by
