Hi there!
∵ 2ᴺᴰ term, a₂ = 24
∴ a + d = 24. --(i)
∵ 5ᵀᴴ term, a₅ = 3.
∴ a + 4d = 3. ---(ii)
Subtracting Eqn. (i) from (ii) :-
(a + 4d) - (a + d) = 3 - 24
a + 4d - a - d = - 21
3d = - 21
d = [tex]\dfrac {- 21}{3}[/tex]
d = - 7
∴ Common difference, d = - 7
Substitute d = -7 in eqn. (i) :-
a + d = 24
a + (-7) = 24
a - 7 = 24
a = 24 + 7
a = 31
∴ First term, a = 31
~ Hope it helps!
