Evaluate the nested brackets accurately: Compute 10 − [9 − {8 − (7 − 6)}] − 5 and choose the correct integer result.

Difficulty: Easy

Correct Answer: 3

Explanation:

Introduction / Context:Nesting of parentheses, braces, and brackets demands inside-out evaluation. This problem reinforces the disciplined approach to evaluate the innermost operation first and move outward step by step to avoid sign mistakes.

Given Data / Assumptions:

  • Expression: 10 − [9 − {8 − (7 − 6)}] − 5.
  • Standard order: parentheses, then braces, then brackets, then remaining operations left to right.

Concept / Approach:Work from the innermost parentheses outward. Keep track of minus signs carefully: subtracting a bracketed value changes signs when distributing over the terms inside.

Step-by-Step Solution:Innermost: (7 − 6) = 1.Next: {8 − 1} = 7.Next: [9 − 7] = 2.Final: 10 − 2 − 5 = 8 − 5 = 3.

Verification / Alternative check:Rewrite as 10 − 2 − 5 after evaluating the bracketed value to ensure no sign inversion errors. This still equals 3.

Why Other Options Are Wrong:−5 results from sign mishandling; 1 and 9 arise from partially completed or incorrectly ordered steps; 5 ignores the second subtraction.

Common Pitfalls:Dropping brackets early; forgetting that subtracting a bracket is subtracting the entire evaluated result; arithmetic slips in the final subtraction.

Final Answer:3

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