What is the sum of the first 8 terms of the geometric series?
120-80+160/3-320/9+
MY WORK:
\(s8= 120(1-(-2/3)^8)/1-(-2/3)\)
\(120(1-(256/6561))/(5/3)\)
\(120(6305/6561)/(5/3)\)
\(120(6305/6561)(3/5)\)
\(2269800/32805\)
(I don't think I'm doing it right please help)
