Giupd em với ạ em xin cảm ơn ạ???????????? October 15, 2020 by RI SƠ Giupd em với ạ em xin cảm ơn ạ????????????
Đáp án: g. \(\left[ \begin{array}{l}x \ge 1\\x \le – 2\end{array} \right.\) Giải thích các bước giải: \(\begin{array}{l}a.DK:3 – 2x > 0 \to \dfrac{3}{2} > x\\b.DK:x \ne 0\\c.DK: – 3 – 7x > 0 \to – \dfrac{3}{7} > x\\d.DK:4x + 1 \ge 0 \to x \ge – \dfrac{1}{4}\\e.DK:x \ge 0\\i.DK: – 6x \ge 0 \to x \le 0\\h.DK:{x^2} – 5x + 6 \ge 0\\ \to \left( {x – 3} \right)\left( {x – 2} \right) \ge 0\\ \to \left[ \begin{array}{l}\left\{ \begin{array}{l}x – 3 \ge 0\\x – 2 \ge 0\end{array} \right.\\\left\{ \begin{array}{l}x – 3 \le 0\\x – 2 \le 0\end{array} \right.\end{array} \right.\\ \to \left[ \begin{array}{l}x \ge 3\\x \le 2\end{array} \right.\\g.DK:\left( {x – 1} \right)\left( {x + 2} \right) \ge 0\\ \to \left[ \begin{array}{l}\left\{ \begin{array}{l}x – 1 \ge 0\\x + 2 \ge 0\end{array} \right.\\\left\{ \begin{array}{l}x – 1 \le 0\\x + 2 \le 0\end{array} \right.\end{array} \right.\\ \to \left[ \begin{array}{l}x \ge 1\\x \le – 2\end{array} \right.\end{array}\) Reply
Đáp án:
g. \(\left[ \begin{array}{l}
x \ge 1\\
x \le – 2
\end{array} \right.\)
Giải thích các bước giải:
\(\begin{array}{l}
a.DK:3 – 2x > 0 \to \dfrac{3}{2} > x\\
b.DK:x \ne 0\\
c.DK: – 3 – 7x > 0 \to – \dfrac{3}{7} > x\\
d.DK:4x + 1 \ge 0 \to x \ge – \dfrac{1}{4}\\
e.DK:x \ge 0\\
i.DK: – 6x \ge 0 \to x \le 0\\
h.DK:{x^2} – 5x + 6 \ge 0\\
\to \left( {x – 3} \right)\left( {x – 2} \right) \ge 0\\
\to \left[ \begin{array}{l}
\left\{ \begin{array}{l}
x – 3 \ge 0\\
x – 2 \ge 0
\end{array} \right.\\
\left\{ \begin{array}{l}
x – 3 \le 0\\
x – 2 \le 0
\end{array} \right.
\end{array} \right.\\
\to \left[ \begin{array}{l}
x \ge 3\\
x \le 2
\end{array} \right.\\
g.DK:\left( {x – 1} \right)\left( {x + 2} \right) \ge 0\\
\to \left[ \begin{array}{l}
\left\{ \begin{array}{l}
x – 1 \ge 0\\
x + 2 \ge 0
\end{array} \right.\\
\left\{ \begin{array}{l}
x – 1 \le 0\\
x + 2 \le 0
\end{array} \right.
\end{array} \right.\\
\to \left[ \begin{array}{l}
x \ge 1\\
x \le – 2
\end{array} \right.
\end{array}\)