alleryCompute 99² (without long multiplication, using (a + b)² or (a − b)²):
A9801
B9901
C10001
D9909
Answer & Solution
Correct answer: A. 9801
99² = (100 − 1)² = 100² − 2·100·1 + 1² = 10000 − 200 + 1 = 9801. Quick check: 99 × 99 = 9801 ✓
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