Let's analyze the arithmetic sequence step-by-step:

Given Sequence:

-3, -8, -13, -18, ...

This is an arithmetic sequence where each term is decreasing by a constant difference. To find the difference:

$d = -8 - (-3) = -8 + 3 = -5$

So, the common difference $d = -5$.

Next Terms Calculation:

We continue the sequence by subtracting $5$ from each term.

1. Next term after $-18$: $-18 - 5 = -23$

2. Term after $-23$: $-23 - 5 = -28$

3. Term after $-28$: $-28 - 5 = -33$

Final Sequence:

The next three terms are: $-23, -28, -33$

Let me know if you want any further details or clarifications.

Follow-up Questions:

1. How is the common difference calculated in an arithmetic sequence?
2. What is the formula for the $n$-th term of an arithmetic sequence?
3. How do you distinguish between arithmetic and geometric sequences?
4. What happens if the common difference is positive instead of negative?
5. Can you apply this concept to sequences with fractions or decimals?

Tip:

Always check for a common difference between consecutive terms to identify an arithmetic sequence quickly!