The given expression is:

$-(-9.4y + 10z + 3.5)$

To simplify this, distribute the negative sign across the terms inside the parentheses:

$= 9.4y - 10z - 3.5$

So, the simplified form of the expression is:

$9.4y - 10z - 3.5$

Would you like more details or have any questions?

Here are 5 related questions to explore further:

1. How would you simplify an expression with multiple negative signs?
2. What happens if variables inside parentheses are multiplied by a constant?
3. How do you handle double negatives in algebraic expressions?
4. What is the distributive property and how is it applied?
5. Can we solve an equation like this one if values for $y$ and $z$ are given?

Tip: Always distribute negative signs carefully when simplifying expressions to avoid errors.