the sum of the first three terms of a sequence Is 42 The fourth term is 24. find u1 and the common difference

Given:

The sum of the first three terms of a sequence Is 42.

The fourth term is 24.

To find:

The  u₁ and the common difference

Step-by-step explanation:

nth term of a sequence is

where, u₁ is first term and d is common difference.

4th term is 24.

          ...(i)

Sum of nth term of an AP is

Sum of first three terms is 42.

Divide both sides by 3.

         ...(ii)

On subtract (ii) from (i), we get

Put d=5 in equation (ii).

Therefore, the first term is and common difference is .

i got 10.28 but that rounds up to 10.3