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Use an identity to compute 102² quickly:

A10404
B10204
C10004
D10404
Answer & Solution
Correct answer: A. 10404
102² = (100 + 2)² = 100² + 2·100·2 + 2² = 10000 + 400 + 4 = 10404. The (a+b)² identity makes large squares easy without long multiplication.
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