Let's solve the expression step by step:

$-1(-1+4)(-1-2)$

Step 1: Simplify inside the parentheses

1. $(-1 + 4) = 3$
2. $(-1 - 2) = -3$

So the expression becomes: $-1 \times 3 \times (-3)$

Step 2: Multiply the terms

1. $-1 \times 3 = -3$
2. $-3 \times (-3) = 9$

Thus, the final answer is: $9$

Would you like any further details or clarification?

Here are 5 related questions to explore:

1. What happens when both numbers in parentheses are negative?
2. How do you handle operations involving negative numbers?
3. What are the rules for multiplying multiple negative numbers?
4. Can you solve more complex expressions with multiple parentheses?
5. How do different operations (addition, subtraction) affect multiplication with negatives?

Tip: When multiplying an odd number of negative factors, the result will always be negative.