Question

\(a)(x^2-3)(2x^2-\dfrac{9}{8})(\sqrt{|x|}-\sqrt{\dfrac{5}{2}})=0\)

\(b)x-5\sqrt{x}=0\)

Answer 1

a: \(\left(x^2-3\right)\left(2x^2-\dfrac{9}{8}\right)\left(\sqrt{\left|x\right|}-\sqrt{\dfrac{5}{2}}\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x^2-3=0\\2x^2-\dfrac{9}{8}=0\\\sqrt{\left|x\right|}-\sqrt{\dfrac{5}{2}}=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x^2=3\\x^2=\dfrac{9}{16}\\\left|x\right|=\dfrac{5}{2}\end{matrix}\right.\Leftrightarrow x\in\left\{-\sqrt{3};\sqrt{3};\dfrac{3}{4};-\dfrac{3}{4};\dfrac{-5}{2};\dfrac{5}{2}\right\}\)

b: \(x-5\sqrt{x}=0\)(ĐKXĐ: x>=0)

\(\Leftrightarrow\sqrt{x}\left(\sqrt{x}-5\right)=0\)

=>x=0 hoặc x=25