Question

Find the 25th term of the sequence -1, 2, 5, 8​

Answer 1

71

Explanation:

This is an arithmetic sequence with n th term

`a_(n)` = a₁ + (n - 1)d

where a₁ is the first term and d the common difference

here d = 2 - (- 1) = 5 - 2 = 8 - 5 = 3 and a₁ = - 1, so

`a_(25)` = - 1 + (24 × 3) = - 1 + 72 = 71