Verified answer

Пошаговое объяснение:

[tex]1) - x = 18 \\ - 1 \times ( - x) = - 1 \times 18 \\ x = - 1 \times 18 \\ x = - 18 [/tex]

[tex]2) - x = - 7 \\ - 1 \times ( - x) = - 1 \times ( - 7) \\ x = - 1 \times ( - 7) \\ x = 7[/tex]

[tex]3) |x| - 4 = 5 \\ |x| = 5 + 4 \\ |x| = 9 \\ x = 9 \\ x = - 9 \\ x_{1} = - 9, x_{2} = 9[/tex]

[tex]4) |x| = 3 \\ x = 3 \\ x = - 3 \\ x_{1} = - 3, x_{2} = 3[/tex]