Geometric Sequnce

Question

Find the 7th term of the geometric sequence: -1,5,-25 ...

Answer 1

The nth term of this geometric sequence can be found by:

 

a_n = a₁r^{(n - 1)}

 

a₇ = (-1)(-5)^{(7 - 1)}

 

a₇ = (-1)(-5)⁶

 

a₇ = (-1)(15,625)

 

a₇ = -15,625