Question

If the common difference of an A. P. is (-3) and the 18th term is (-5), then find the first term of the series?

Answer 1

Step-by-step explanation:

nth term =a+(n-1)d

Where a = first term , d = common difference and n = term

Its given that

nth term = -5

n = 18

d = -3

Now substitute the values

nth term = a+(n-1)d

-5 = a + (18–1)-3

-5 = a + (17)-3

-5 = a -51

a = 51–5

a = 46