Question

In an AP, the common difference d and seventh term(a7)is 154.Then find the first term

Answer 1

here d=154
a+6d=154
a+6(154)=154
a+924=154
a=-770

Answer 2

Solution :-

Although this question is clear, but I have solved it.

Let the first term of the given AP be 'a'

Common difference = d (given)

7th term or a7 = 154 (given)

an = a + (n - 1)d

⇒ 154 = a + (7 - 1)d

⇒ a + 6d = 154

⇒ a = 154 - 6d

So, the first term is 154 - 6d

Answer.