Question

in a G.P. T2 + T5 =216 and T4 : T6 = 1:4 find first term​

Answer 1

Answer:

The first term is 12

Step-by-step explanation:

In a G.P

t2 + t5 = 216

ar + ar⁴ = 216 → (1)

t4 : t6 = 1:4

ar³:ar⁵ = 1:4

1:r² = 1:4

By comparing the ratios,

r² = 4

r = 2

Substituting r = 2 in (1)

2a + 16a = 216

18a = 216

a = 216/18

a = 12