Question

given the arithmetic sequence 71,65,59 ... if a(n) is -43 what is the value of n

Answer 1

a = 71, d = -6
term(n) = a + (n-1)d
-43 = 71 + (n-1)(-6)
-43 = 71 - 6n + 6
6n = 120
n = 20

Answer 2

Answer