Question

completati spatiile libere pentru a obtained propozitii adevarate​

Answer 1

Explicație pas cu pas:

a) x ∈ {0; 1; 2}, x ∈ N

$|x| < \sqrt{5} \\ - \sqrt{5} < x < \sqrt{5} \\ 2 = \sqrt{4}< \sqrt{5}$

b) x ∈ {-2; -1; 0; 1; 2}, x ∈ Z

$|x| < 7 \\ - 7 < x < 7$

c) x ∈ {-1; 1}, x ∈ Z*

$| \frac{x}{3} | \leqslant 0.(3) < = > | \frac{x}{3} | \leqslant \frac{3}{9} \\ | \frac{x}{3} | \leqslant \frac{1}{3} < = > |x| | \leqslant 1 \\ - 1 \leqslant x \leqslant 1$