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:
Set a = 0.538 and b = 0.462.a − b = 0.538 − 0.462 = 0.076.a + b = 0.538 + 0.462 = 1.000.So numerator = (a − b)(a + b) = 0.076 × 1.000 = 0.076.Denominator: 1 − 0.924 = 0.076.Quotient = 0.076 / 0.076 = 1.Verification / Alternative check:
Because a + b = 1 exactly, the numerator equals a − b. Direct subtraction confirms both numerator and denominator equal 0.076.Why Other Options Are Wrong:
Common Pitfalls:
Final Answer:
1
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