To simplify the expression $(2x - 3y) - (8x + 6y + 4)$, follow these steps:

1. Distribute the negative sign across the second group: $(2x - 3y) - 8x - 6y - 4$

2. Combine like terms:

   • Combine the $x$ terms: $2x - 8x = -6x$
   • Combine the $y$ terms: $-3y - 6y = -9y$
   • The constant term remains: $-4$

So, the simplified expression is: $-6x - 9y - 4$

Would you like more details or have any questions?

Here are 5 related questions:

1. How would you factor the expression $-6x - 9y - 4$?
2. What happens if you add $10$ to the simplified expression?
3. How do you simplify $2(3x - 4y) - 3(x + 2y)$?
4. Can you explain the difference between like terms and unlike terms?
5. What are the steps to expand and simplify $(x + 2)(x - 3)$?

Tip: When simplifying expressions, always distribute any negative signs and combine like terms carefully to avoid mistakes.