Question

BT1: Tìm x, biết:

6) \(\dfrac{10}{x}< \dfrac{x}{11}< \dfrac{12}{x}\)

Answer 1

\(\cdot\dfrac{10}{x}< \dfrac{x}{11}\Rightarrow x^2< 110\Rightarrow-\sqrt{110}< x< \sqrt{110}\\ \cdot\dfrac{x}{11}< \dfrac{12}{x}\Rightarrow x^2< 132\Rightarrow-\sqrt{132}< x< \sqrt{132}\)\(\Rightarrow-\sqrt{132}< x< \sqrt{132}\)

Answer 2

\(\dfrac{10}{x}< \dfrac{x}{11}< \dfrac{12}{x}\)

<=> \(\dfrac{110}{11x}< \dfrac{x^2}{11x}< \dfrac{132}{11x}\)

<=> 110 < x² < 132
<=> x² = 121
<=> x = 11
@Khánh Linh