1. The problem is to simplify the expression $6 + 3(2) - 4 - (5 + 3)$. 2. Use the order of operations: parentheses first, then multiplication, then addition and subtraction from left to right. 3. Calculate inside the parentheses: $5 + 3 = 8$. So the expression becomes $6 + 3(2) - 4 - 8$. 4. Next, multiply: $3(2) = 6$. Now the expression is $6 + 6 - 4 - 8$. 5. Perform addition and subtraction from left to right: $6 + 6 = 12$ $12 - 4 = 8$ $8 - 8 = 0$. 6. The final answer is $0$.