Question

check whether 73 is a term of the AP 1,5,9,...​

Answer 1

Answer:

a = 1

d = 5-1 = 4

t = 73

t = a+(n-1)d

73 = 1+(n-1)4

72 = (n-1)4

18 = n-1

n = 19

So, 73 is the 19th term of the AP.

Answer 2

73 is the 19th term......