To simplify the expression $10 - 5(9n - 9)$, follow these steps:

Step 1: Distribute the $-5$

Distribute the $-5$ across the terms inside the parentheses:

$-5(9n) = -45n$ $-5(-9) = 45$

So, the expression becomes:

$10 - 45n + 45$

Step 2: Combine like terms

Now, combine the constants $10$ and $45$:

$10 + 45 = 55$

Thus, the simplified expression is:

$-45n + 55$

So, the final simplified expression is:

$-45n + 55$

Would you like more details or have any questions about this?

Related Questions:

1. How do you distribute a negative sign in an expression?
2. What are "like terms" and how do you combine them?
3. What would the expression look like if there was a different coefficient inside the parentheses?
4. How can you check the simplified expression for correctness?
5. How do you handle parentheses in algebraic expressions with more complex terms?

Tip: When distributing a negative sign, ensure you multiply both terms inside the parentheses by the negative value.