Question

√1/-2x+5 có nghĩa khi nào

Answer 1

\(\sqrt{\dfrac{1}{-2x+5}}\)

\(-2x+5>0\Leftrightarrow x< \dfrac{5}{2}\)

Answer 2

\(\sqrt{\dfrac{1}{-2x+5}}\\ ĐK:\dfrac{1}{-2x+5}\ge0\Leftrightarrow-2x+5>0\left(-2x+5\ne0;1>0\right)\\ \Leftrightarrow x< \dfrac{5}{2}\)