Problema Solution

Find a60 (the 60th term)of the arithmetic sequence, given that the first term, a1. is 35 and the common difference, d, is -3

Answer provided by our tutors

We can write an Arithmetic Sequence as a rule:

an = a1 + d(n-1)

a1 = 35 (the first term)
d = -3 (the "common difference")

an = 35 + (-3)(n - 1)

an = 38 - 3n

For n = 60 we have:

a60 = 38 - 3*60

a60 = -142

The 60th term is -142.