Given the intervals 2 x 5 and -4 y 7, find the bounds for x+y and x-y.

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Exercice 1: Encadrements

Given the intervals:
$2 \le x \le 5$
$-4 \le y \le 7$

1. Encadrer $x+y$: To find the bounds for $x+y$, we add the lower bounds and the upper bounds:

   $$2 + (-4) \le x+y \le 5 + 7$$ $$\boxed{-2 \le x+y \le 12}$$

2. Encadrer $x-y$: To find the bounds for $x-y$, we first find the bounds for