Question

I)
Find the first term of a G.P. whose fifth term is 243 and the
common ratio 3.​

Answer 1

first term = 3

Explanation:

The n th term of a GP is

`a_(n)` = a₁
`(r)^(n-1)`

where a₁ is the first term and r the common ratio

Here r = 3 and a₅ = 243 , thus

a₁ ×
`3^(4)` = 243

a₁ × 81 = 243 ( divide both sides by 81 )

a₁ = 3