Question

What is the 32nd term of the arithmetic sequence where a1 = 15 and a13 = -57?

A) -171
B) -165
C) -158
D) -151

Answer 1

(-57 - 15)/(13 - 1) = -6

a(n) = 15 - 6·(n - 1)

a(32) = 15 - 6·(32 - 1) = -171