How do you complete the statement for the arithmetic sequence: -14 is the __ term of 2 1/5, 2, 1 4/5,...?

1 Answer
Feb 20, 2017

82nd

Explanation:

We know that the nth term of an arithmetic sequence is given by t_n = a + (n - 1)d. Our first term is 2 1/5 = 11/5 and our common difference is -1/5.

-14 = 11/5 + (n - 1)-1/5

-14 = 11/5 - 1/5n + 1/5

-14 = 12/5 - 1/5n

-14 - 12/5 = -1/5n

-82/5 = -1/5n

n = (-82/5)/(-1/5)

n = 82

Hopefully this helps!