Evaluate, using (a + b)(a - b)= a^2 - b^2,999 1001 - Vidyadip

Question

Evaluate, using $(a + b)(a - b)= a^2 - b^2,999 \times 1001$

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Answer

$999 \times 1001$
$= (1000 - 1) \times (1000 + 1)$
$= (1000)^2 - (1)^2$
$= 1000000 - 1$
$= 999999.$

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