Question

Find the 60th term of the arithmetic sequence -10, 8, 26,

Answer 1

a(60) = 1052

Explanation:

Note that when going from -10 to 8 we make a jump of 18; similarly, going from 8 to 26, we make a jump of 18 again. Thus, the common difference in this arithmetic sequence is 18, and given that the first term is -10, the sequence must be:

a(n) = -10 + 18(n - 1)

Therefore, the 60th term is

a(60) = -10 + 18(59), or

a(60) = 1052

Answer 2

a₆₀ = 1052

Explanation:

There is a common difference between consecutive terms , that is

8 - (- 10) = 26 - 8 = 18

This indicates the sequence is arithmetic with nth term

`a_(n)` = a₁ + (n - 1)d

where a₁ is the first term and d the common difference

Here a₁ = - 10 and d = 18 , then

a₆₀ = - 10 + (59 × 18) = - 10 + 1062 = 1052