Final answer:
To simplify the expression, evaluate the innermost parentheses first and then combine the simplified expressions.
Step-by-step explanation:
To simplify the expression 9+[a-{2b-(6a+b-4)+2a} - {a-(b-2)}], we can start by evaluating the innermost parentheses first.
1. Simplify the expression inside the first set of parentheses. (-6a - b + 4)
2. Simplify the expression inside the second set of parentheses. (b - 2)
3. Simplify the expression inside the third set of curly braces. (a - (b - 2))
4. Combine all the simplified expressions and evaluate the final expression.