Topic: Algebraic Identities
Mathematics Quiz
Question: Evaluate \(7^2-5^2\).
Answer & Explanation
Correct: B — \(24\)
Reason: Use \(a^2-b^2=(a-b)(a+b)\). Here \(a=7,b=5\): \((7-5)(7+5)=2\times12=24\). Direct squaring also gives \(49-25=24\).
Reason: Use \(a^2-b^2=(a-b)(a+b)\). Here \(a=7,b=5\): \((7-5)(7+5)=2\times12=24\). Direct squaring also gives \(49-25=24\).
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