Explicație pas cu pas:
c)
[tex] |x - 1| < 3[/tex]
[tex] - 3 < x - 1 < 3 \\ - 3 + 1 < x < 3 + 1 \\ - 2 < x < 4[/tex]
[tex]C = \{-1; 0; 1; 2; 3\}[/tex]
d)
[tex] - 18 < x \leqslant 2[/tex]
[tex]D = \{-16; -14; -12; -10; -8; -6; -4; -2; 0; 2\} \\ [/tex]
e)
[tex] |2x - 1| < 19 \\ - 19 < 2x - 1 < 19 \\ - 19 + 1 < 2x < 19 + 1 \\ - 18 < 2x < 20 \\ - 9 < x < 10[/tex]
[tex]E = \{-6; -3; 0; 3; 6; 9\} \\ [/tex]
f)
[tex] \frac{13}{x + 2} \in\mathbb{N} \\ [/tex]
[tex]= > x + 2 \in \{1; 13\}[/tex]
[tex]x + 2 = 1 = > x = - 1[/tex]
[tex]x + 2 = 13 = > x = 11[/tex]
[tex]F = \{-1; 11\} \\ [/tex]
