If the sum of the first two terms of a G.P is 3 and the sum of the second and third term is -6, find the sum of the first term and common ratio.

Answer 1

a + ar = 3 -----> a(1+r) = 3
ar + ar^2 = -6 ---> ar(1+r) = -6

divide the 2nd equation by the first
r = -2
now sub that into the first to get a
and you are all set