Schoolcrop

(Q28).The sum of the 4^th and 8^th terms of an AP is 24 and the sum of the 6^th and 10^th terms is 44. Find the first three terms of the AP.

Given an A.P in which a₄ + a₈ = 24

⇒ a + d + a + d =

⇒ a + d =

⇒ a + d = ……. (1)

and a₆ + a₁₀ = 44

⇒ a + d + a + d =

⇒ a + d =

⇒ a + d = ……. (2)

Also a + d =

⇒ a + () =

⇒ a + =

⇒ a = – = -

∴ The A.P is a, a + d, a + 2d, ……

i.e., – 13, (- 13 + ), (-13 + 2 × )…

⇒ -13, -, -, …….