Write a formula

Question

Write a formula for the general term (the nth term) of the geomteric sequence. Then use the formula for a_n to find a_7, the seventh term of the sequence.

 

3, 15, 75, 375

Answer 1

For a geometric sequence:

 

a_n = a₁r^n-1, where n = number of terms, r = common ratio, a₁ = first term

 

a₇ = (3)(5)⁶

a₇ = (3)(15625)

a₇ = 46875