Question

va rogggg!!!! multtttt​

Answer 1

Explicație pas cu pas:

a)

$\dfrac{7}{2x + 1} \in \mathbb{Z} \iff (2x + 1) \in \mathcal{D}_{7} \\ (2x + 1) \in \Big\{- 7; - 1;1;7\Big\}\ \Big| -1$

$2x \in \Big\{- 8; - 2;0;6\Big\}\ \Big| : 2 \iff x \in \Big\{- 4; - 1;0;3\Big\}$

$x \in \mathbb{N} \implies x = 0$

b)

$- 3 \leqslant x \leqslant 7$

$x \geqslant - 3 \iff x + 3 \geqslant 0 \\ \implies |x + 3| = x + 3$

$x \leqslant 7 \iff x - 7 \leqslant 0 \\ \implies |x - 7| = 7 - x$

$a = x + 3 + 7 - x = \bf 10$

c)

= (-5;5)

Answer 2

Răspuns:

Explicație pas cu pas: