Question

answer it please please
and
explane it....​

Answer 1

Answer:

Step-by-step explanation:

We know that nth term of AP is given by, tₙ = a + (n-1)d where a is the first term, n is the number of terms and d is the common difference.

Given t₃ = 8 and d = 3.

So third term of AP, t₃ = a + (3 - 1)3 = 8

=> a + 6 = 8

=> a = 2.

Thus first term of AP is 2.

We know that Sum of n terms of AP is given by Sₙ= n/2(2a + (n - 1)d)

= S₅ = 5/2(2*2 + (5-1)3) = 5/2(4+12) = 5*8 = 40.