Stuck please help

Question

what is the eighth term for the geometric sequence given by the explicit rule a_n=-(2)^n-1?

Answer 1

The 8th term specifies what number of n you need. So, a_n is a₈ in this case, and the rule for this term would be -(2)^8-1, or -2⁷. 2⁷ is 2 multiplied by itself 7 times. 2⁷ = 128. The negative out front means that the solution is taking the negative case, or -128. If the negative were inside the parentheses, you would need to determine if the power were even or odd, and adjust your power accordingly. (Even means that the solution is always positive, odd means that the solution can be negative.)