Final answer:
To find the first five terms of the arithmetic sequence with a1=1 and d=5, we add the common difference of 5 to each preceding term. The terms are 1, 6, 11, 16, and 21, making the correct option a) 1, 6, 11, 16, 21.
Step-by-step explanation:
The question asks to list the first five terms of the arithmetic sequence with given first term a1 equals 1 and common difference d equals 5. An arithmetic sequence is a sequence of numbers in which each term after the first is found by adding a constant, called the common difference, to the previous term. So, for the first five terms:
- First term: a1 = 1
- Second term: a2 = a1 + d = 1 + 5 = 6
- Third term: a3 = a2 + d = 6 + 5 = 11
- Fourth term: a4 = a3 + d = 11 + 5 = 16
- Fifth term: a5 = a4 + d = 16 + 5 = 21
Hence, the correct option is a) 1, 6, 11, 16, 21.