[tex]5)A=\left \{ x\:\in\:\mathbb{{Z}^{*}}\:|\:|x|<4 \right \}[/tex]
[tex] |x| = | - x|=x [/tex]
[tex] |1| = | - 1| = 1 < 4[/tex]
[tex] |2| = | - 2| = 2 < 4[/tex]
[tex] |3| = | - 3| = 3 < 4[/tex]
[tex] = > x \in \: \left \{ \pm1,\pm2,\pm3\right \}[/tex]
[tex] = > A = \left \{ \pm1,\pm2,\pm3\right \}[/tex]
[tex]6) - \overline{7a48}[/tex]
[tex]\:\:\: \:\:\:- \overline{73a8}[/tex]
[tex]pt. \: a = 1 \: = > - 7148 > - 7318[/tex]
[tex]pt. \: a = 2 = > - 7248 > - 7328[/tex]
[tex]pt. \: a = 3 = > - 7348 < - 7338[/tex]
[tex]pt. \: a = 4 = > - 7448 < - 7348[/tex]
[tex]pt. \: a = 5 = > - 7548 < - 7358[/tex]
[tex]pt. \: a = 6 = > - 7648 < - 7368[/tex]
[tex]pt. \: a = 7 = > - 7748 < - 7378[/tex]
[tex]pt. \: a = 8 = > - 7848 < - 7388[/tex]
[tex]pt. \: a = 9 = > - 7948 < - 7398[/tex]
