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प्रश्न
Evaluate, using (a + b)(a - b)= a2 - b2.
4.9 x 5.1
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उत्तर
4.9 x 5.1
= (5 - 0.1) x (5 + 0.1)
= (5)2 - (0.1)2
= 25 - 0.01
= 24.99.
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