The fifth term of an arithmetic sequence is 23 and the 12th is 72. determine the next three terms and general formula

Question

asked Jan 17, 2022 222k views

1 Answer

Amar Banerjee · Answer 1 · 2022-01-21T09:07:23+0000

Answer:

first three terms are -5 , 2, and 9

Explanation:

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

term5 = a+ 4d = 23

term12 = a + 11d = 72

subtract them

7d = 49

d = 7

sub into a+4d = 23

a + 28 = 23

a = -5