Difficulty: Easy
Correct Answer: 1
Explanation:
Introduction / Context:
This question highlights the algebraic identity a^2 − b^2 = (a − b)(a + b). Recognizing this pattern avoids tedious decimal squaring. Pairing that with a straightforward subtraction in the denominator gives a clean simplification to an integer answer.
Given Data / Assumptions:
Concept / Approach:
Use the identity a^2 − b^2 = (a − b)(a + b). Compute (a − b) and (a + b) once; then multiply. For the denominator, simple subtraction suffices. Compare numerator and denominator to see if cancellation occurs.
Step-by-Step Solution:
Verification / Alternative check:
Why Other Options Are Wrong:
Common Pitfalls:
Final Answer:
Discussion & Comments