Final answer:
The 71st term of the arithmetic sequence 1, 3, 5, 7, ... is equal to 141. To find this, the formula for the n-th term of an arithmetic sequence was applied and solved for n.
Step-by-step explanation:
To find which term of the arithmetic sequence 1, 3, 5, 7, ... is equal to 141, we use the formula for the n-th term of an arithmetic sequence: a_n = a_1 + (n - 1)d, where a_n is the n-th term, a_1 is the first term, d is the common difference, and n is the term number.
In this sequence, a_1 = 1 and the common difference d = 2 (since each term increases by 2). Plugging the values into the formula, we are looking for n such that 141 = 1 + (n - 1)×2.
Solving for n, we get:
- 141 = 1 + 2n - 2
- 141 = 2n - 1
- 142 = 2n
- n = 142 / 2
- n = 71
Therefore, the 71st term of the sequence is equal to 141.