Obtain the sum of the first 56 terms of an A.P. whose 19th and 38th terms are 52 and 148 respectively.

Obtain the sum of the first 56 terms of an A.P. Whose 18th and 39th terms are 52 and 148 respectively. (1) Usint t_(18) and t_(39) find two simultaneous equations in variables a and d. (2) Using these equations, find S_(56)

Obtain the sum of 56 terms of an A.P. whose 19^(th) and 28^(th) terms are 52 and 148 respectively.

Obtain the sum of 56 terms of an A.P whose 19th and 38th term are 52 and 148 respectively.

Find the sum of first 17 terms of an AP whose 4th and 9th terms are -15 and -30 , respectively.

Find the sum of first 17 terms of an AP whose 4th and 9th terms are -15 and -30 , respectively.

The first term of an A.P. whose 8th and 12th term are 39, 59 respectively.

Find the sum of the first 40 terms of the A.P. whose 4th term is 8 and 6th term is 14.

Find the sum of the first ten terms of the A.P. whose 4th term is -15 and 9th term is -30

Find the sum of first 25 terms of an A.P. whose 4th term is 13 and 22nd term is 67.