Question

Sa se determine multimea nr reale pentru care -4 ≤ 3x+2≤4. b) Sa se determine multimea valorilor lui x pentru care -4<3x+2<4

Answer 1

$1)-4 \leq 3x+2 \leq 4 \ \ \ |(-2) \\\\ -6 \leq 3x \leq 2 \ \ \ |:3 \\\\ -2 \leq x \leq \frac{2}{3} \longrightarrow x \in [-2;\frac{2}{3}] \to \{-2;-1;0;\frac{2}{3} \} \\\\\\ 2)-4\ \textless \ 3x+2\ \textless \ 4 \ \ \ |(-2) \\\\ -6\ \textless \ 3x\ \textless \ 2 \ \ \ |:3 \\\\ -2\ \textless \ x\ \textless \ \frac{2}{3} \longrightarrow x \in (-2;\frac{2}{3} )\to \{-1;0 \}$