Thu gọn ​biểu thức: \(\sqrt {9{{\left( {x + \frac{1}{2}} \right)}^2}} \left( {x \ge - \frac{1}{2}} \right) \)

* Hướng dẫn giải

Ta có: \(\sqrt {9{{\left( {x + \frac{1}{2}} \right)}^2}} = \sqrt 9 .\sqrt {x + \frac{1}{2}} = 3.\left| {x + \frac{1}{2}} \right| \)

\(= 3\left( {x + \frac{1}{2}} \right)\left( { \text{ Do } x \ge - \frac{1}{2} \Rightarrow x + \frac{1}{2} \ge 0} \right)\)