The expression $-(a - b) - b$ can be simplified as follows:

1. Distribute the negative sign across the first parentheses: $-(a - b) = -a + b$ Now the expression becomes: $-a + b - b$

2. Combine the like terms $b - b$: $-a + 0 = -a$

Thus, the simplified result is: $-a$

Let me know if you'd like further clarification or have any other questions!

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Here are 5 related questions to explore:

1. How do you simplify more complex expressions involving multiple parentheses?
2. What is the difference between distributive property and combining like terms?
3. How does this simplification process work with terms involving exponents?
4. What are the rules for simplifying expressions with negative signs?
5. Can you explain how to apply the distributive property to expressions with variables?

Tip: Always double-check your distribution and sign changes when working with negative signs in algebra to avoid errors!