Answer:
B)1-x≤-1 OR 1-x≥1
[tex]S=\{x\in\mathbb{R}| x\le 0\quad \text{or}\quad x\ge 2 \}[/tex]
Step-by-step explanation:
[tex]2|1-x|+1\geq 3[/tex]
[tex]2|1-x|\geq 2[/tex]
[tex]|1-x|\geq 1[/tex]
Once we have an absolute value inequality, remember that:
For a > 0
[tex]\boxed{\text{If } |x|\leq a \Longleftrightarrow -a\leq x \leq a}[/tex]
[tex]\boxed{\text{If } |x|\geq a \Longleftrightarrow x\leq -a \text{ or } x\geq a }[/tex]
Therefore,
[tex]1-x\le -1\quad \text{or}\quad 1-x\ge 1[/tex]
Solving
[tex]1-x\le -1 \Longleftrightarrow x\geq 2[/tex]
[tex]1-x\ge 1 \Longleftrightarrow x\leq 0[/tex]
We have
[tex]x\geq 2 \quad \cup \quad x \leq 0[/tex]
[tex](-\infty, 0] \cup [2, \infty)[/tex]
[tex]S=\{x\in\mathbb{R}| x\le 0\quad \text{or}\quad x\ge 2 \}[/tex]