Given an arithmetic progression with its first three terms as 2t,5t−1 and 6t+2, for some real number t. Find the value of the fourth term of the sequence.
2t, 5t – 1, and 6t + 2 are the first three terms of an arithmetic sequence.
To find the common difference of A.P. third term – second term = second term – first term will give you the value of t.
6t + 2 – 5t + 1 = 5t – 1 - 2t
t + 3 = 3t – 1
2t = 4
t = 2.
Substituting 2 for t in the expressions of the three first terms of the sequence, one
sees that they are 4, 9 and 14, respectively. The common difference between consecutive terms for this arithmetic sequence is 5.
Therefore, the fourth term is 14 + 5 = 19