Question

if the 3rd term of an AP is 600 and 7th term is 700 then the first term is______​

Answer 1

Answer:

We have,

a3 =600 and a7 =700

⟹a+2d=600 ........ (1)

and a+6d=700 ......... (2)

Solving these equation, we get

a=550 and d=25

Answer 2

Answer:

Let a be the first term and d be the common difference of the A.P.

a + 2d = 600

a + 6d = 700

So first term a = 550