Question

The first term of a G.p are as follows: m, m^2+4, 16m find the 5th term

Answer 1

Answer:

512

Step-by-step explanation:

In a geometric sequence, the ratio between the second term and the first term is equal to the ratio between the third term and the second term.

(m² + 4) / m = 16m / (m² + 4)

Solve:

(m² + 4)² = 16m²

m² + 4 = 4m

m² − 4m + 4 = 0

(m − 2)² = 0

m = 2

The first three terms of the geometric sequence are therefore 2, 8, 32.

The common ratio is 4, and the first term is 2.  So the 5th term is:

a = 2 (4)⁵⁻¹

a = 512