The first term of the arithetic sequence is 87.
Explanation:
Given,
and common difference,(d)

Let the first term of the arithetic sequence = a
To find, the first term of the arithetic sequence = ?
We know that,
The nth term of the arithmetic sequence,

⇒

⇒

⇒

⇒

⇒ a = 87
Hence, the first term of the arithetic sequence is 87.