Question

What is the 25th term given a₁ = 8 and r = 2?

Answer 1

134217728

Explanation:

The geometric sequence formula is:

`\displaystyle{a_n = a_1r^(n-1)}`

We know that
`\displaystyle{a_1=8}` and
`\displaystyle{r=2}`, we also want to find the 25th term, substitute n = 25:

`\displaystyle{a_(25)=8\cdot 2^(25-1)}\\\\\displaystyle{a_(25)=8\cdot 2^(24)}\\\\\displaystyle{a_(25)=134217728}`

Therefore, the 25th term of sequence is 134217728