Answer:
- arithmetic, first term 2: an=2+3(n-1)
- arithmetic, first term 3: an=3+4(n-1)
- geometric, first term 3: an = 3·4^(n-1)
- geometric, first term 4: an = 4·2^(n-1)
Explanation:
The usual formula for an arithmetic sequence with first term a1 and common difference d is ...
an = a1 + d(n-1)
The usual formula for a geometric sequence with first term a1 and common ratio r is ...
an = a1·r^(n-1)
The problem statements give the nature of the sequence, the first term, and the common difference or ratio. All that is required is that you put the given numbers into the appropriate formula.
For these, you don't even need to look past the sequence type (arithmetic or geometric) and the first term. Just knowing that much allows you to choose the correct answers.