Question

Given the following sequence, find the 14th term: 3, 1, –1, –3, –5, . . .
a. –28
b. –25
c. –23
d. –21

Answer 1

C.-23 Just subtract two every time until you get to the 14 th number 

Answer 2

3, 1, -1, -3, -5
 -2  -2  -2  -2

a(n) = a₁ + d(n - 1)
a(n) = 3 - 2(n - 1)
a(n) = 3 - 2(n) + 2(1)
a(n) = 3 - 2n + 2
a(n) = -2n + 3 + 2
a(n) = -2n + 5
   a₁₄ = -2(14) + 5
   a₁₄ = -28 + 5
   a₁₄ = -23

The answer is C.