To simplify the expression $7(9 + 10n)$, we apply the distributive property:

$7 \times 9 + 7 \times 10n$

This results in:

$63 + 70n$

So, the simplified expression is:

$63 + 70n$

Let me know if you need more details or further clarification!

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Here are five related questions:

1. What is the value of $n$ if the expression equals 100?
2. How would the expression change if the number 9 was replaced with 5?
3. What happens if you factor out the 7 from the expression $63 + 70n$?
4. Can you simplify the expression $7(2 + 3n) + 4(5 + 6n)$?
5. How would you solve for $n$ in the equation $7(9 + 10n) = 140$?

Tip: When working with distributive property, always multiply each term inside the parentheses by the factor outside!