The 2nd term in Geometric sequence is -4 and the 5th is 32 ,find the general formula \term and the first 3 terms ,find the 18th term

Answer 1

a r^0 + a r^1 + a r^2 +.... ar^(n-1)
the 18th term is ar^17
if a = 2 and r = -2
then a r^17 = 2 (-2)^17
= - 2^17 = -131072