Question

Find the 9th term of the geometric sequence 9, -27, 81...

Answer 1

a9= 59049

Explanation:

Find the r.

R= 81/-27

R= -3

a1= 9

a2= -27

a3= 81

a4= 81*-3= -243

a5= -243*-3= 729

a6= 729*-3= -2187

a7= -2187*-3= 6561

a8= 6561*-3= -19683

a9= -19683*-3= 59049