Question

Find the 7th term of the geometric sequence with the given terms.

1. a4=54, a5=162
2.a4=-4, a6=-100

Answer 1

1. 1458

2. 500 or -500

Explanation:

1. a4=54, a5=162

r = 162/54 = 3

a7 = a5 × r²

= 162 × 3² = 1458

2.a4=-4, a6=-100

r² = -100/-4 = 25

r = +/- 5

a7 = a6 × r

= -100 × +/- 5

= +/- 500