Question
In a decreasing gp the sum of the second and third terms is 36 and the difference between these two terms is 18.find a)the first term b)the nth term
Answers
oobleck
ar + ar^2 = 36
ar - ar^2 = 18
dividing,
r(1+r)/(r(1-r)) = 2
1+r = 2(1-r)
r = 1/3
a = 81
The GP is 81,27,9,3,...
ar - ar^2 = 18
dividing,
r(1+r)/(r(1-r)) = 2
1+r = 2(1-r)
r = 1/3
a = 81
The GP is 81,27,9,3,...
eniola
please show solution
Musa
right