Question

Va rog ajutați-mă, ofer 30.
Nu trebuie neaparat toate problemele rezolvate!

Answer 1

1.

$\dfrac{2x-1}{-3}\in[-1;\ 3] |_{\cdot(-3)} \Leftrightarrow 2x-1\in [-9,\ 3]|_{+1}\Leftrightarrow 2x\in[-8,\ 4] |_{:2} \Leftrightarrow x\in[-4,\ 2]$

2.

$\it \begin{cases}\it\dfrac{1}{x-2}<0 \Rightarrow x-2<0 \Rightarrow x<2 \Rightarrow x\in(-\infty,\ 2)\\ \\ \\ \it\dfrac{2x+1}{3}-\dfrac{1+x}{2}>2|_{\cdot6} \Rightarrow4x+2-3-3x>12 \Rightarrow x>13 \Rightarrow x\in(13,\ \infty)\end{cases}\Rightarrow \\ \\ \\ \Rightarrow x\in (-\infty,\ 2)\cap(13,\ \infty)=\varnothing$