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• Mauritius

Evaluate:
$29 \times 31$

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Answer:

$899$

Step by Step Explanation:

1. We know that
   $a^2 - b^2 = (a - b) (a + b)$
2. Thus, $$\begin{aligned} 29 \times 31 & = (30 - 1) \times (30 + 1) && [\text{Using}, a^2 - b^2 = (a - b) (a + b)] \\ & = [(30)^2 - 1^2] \\ & = (900 - 1) \\ & = 899 \end{aligned}$$

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