Question

What is the 41st term of the arithmetic sequence where a base(1) = 16 and a base(15) = -40 ?

Answer 1

a(n) = a(1) + d(n - 1)
-4 = 16 + d(16 - 1)
-40 = 16 + 15d
-56 = 15d
d = -3.73?

This is where I'm stuck.

I understand that the next formula is:

a(n) = a(1) + d(n - 1)

But is -3.73 correct?

Answer 2

-40= 16 + d(15 - 1) so d=-4

Answer 3

a[41) =-144