## anonymous 5 years ago find the nth term of each geometric sequence. a1=2,n=4,r=-2 explain this please.

so if a = 2, r = -2, the sum for a geometric series is a/1-r, this tells you the form of the series $\sum_{}^{}ar^n$. so then you plug in your values, and have $\sum_{0}^{\infty}-4^n$, so the 4th term is -4^4.