To simplify the expression $-5x + 8 - 3x - 8$, follow these steps:

1. Combine like terms (terms involving $x$ and constants separately):

   $-5x - 3x + 8 - 8$

2. Simplify the terms involving $x$:

   $-5x - 3x = -8x$

3. Simplify the constant terms:

   $8 - 8 = 0$

So, the simplified expression is:

$-8x$

Would you like more details or have any other questions?

Here are 5 related questions you might find helpful:

1. How do you simplify expressions with more than two variables?
2. What are the rules for combining like terms?
3. How do you factor expressions with negative coefficients?
4. Can you solve an equation after simplifying the expression?
5. What happens if you add or subtract the same variable multiple times in an equation?

Tip: When simplifying expressions, always group like terms together first to make the process easier.