Mathematics
posted by Elom Charles .
The second term of a G.P is 12 more than the first term,given that the common ratio is half of the first term.find the fourt term of the G.P.

ar = a+12
r = a/2
a^2/2 = a+12
a^2  2a  24 = 0
(a6)(a+4)
so, a=6, r=3
or, a=4, r=2
6, 18, 54, 162, ...
or
4, 8, 16, 32, ...