Tìm \(x\) biết: \(\frac{{ - 11}}{{12}} + \frac{5}{6} \le \frac{x}{{36}} \le \frac{7}{9} - \frac{3}{4}\)

Câu hỏi :

Tìm \(x\) biết: \(\frac{{ - 11}}{{12}} + \frac{5}{6} \le \frac{x}{{36}} \le \frac{7}{9} - \frac{3}{4}\) 

A. \(x \in \left\{ { - 3;\,\, - 2;\,\, - 1;\,\,0} \right\}\).

B. \(x \in \left\{ { - 3;\,\, - 2;\,\, - 1;\,\,0;\,\,1;\,\,2} \right\}\).

C. \(x \in \left\{ { - 3;\,\, - 2;\,\, - 1;\,\,0;\,\,1} \right\}\).

D. \(x \in \left\{ { - 2;\,\, - 1;\,\,0;\,\,1} \right\}\).

* Đáp án

C

* Hướng dẫn giải

\(\,\,\,\,\,\,\frac{{ - 11}}{{12}} + \frac{5}{6} \le \frac{x}{{36}} \le \frac{7}{9} - \frac{3}{4}\)

\( \Rightarrow \frac{{ - 33}}{{36}} + \frac{{30}}{{36}} \le \frac{x}{{36}} \le \frac{{28}}{{36}} - \frac{{27}}{{36}}\)

\( \Rightarrow \frac{{ - 3}}{{36}} \le \frac{x}{{36}} \le \frac{1}{{36}}\)

\( \Rightarrow  - 3 \le x \le 1\)

Mà \(x \in \mathbb{Z} \Rightarrow \)\(x \in \left\{ { - 3;\,\, - 2;\,\, - 1;\,\,0;\,\,1} \right\}\).

Vậy \(x \in \left\{ { - 3;\,\, - 2;\,\, - 1;\,\,0;\,\,1} \right\}\).

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