Question

Answer 1

x=1/2 và 1/4 bạn nhé

Answer 2

b) \(\dfrac{1}{10}:\left(\dfrac{3}{4}-2x\right)^{^{ }2}=0,4\)
            \(\left(\dfrac{3}{4}-2x\right)^2=\dfrac{1}{10}.\dfrac{5}{2}\)
            \(\left(\dfrac{3}{4}-2x\right)^2=\dfrac{1}{4}\)
=> \(\left\{{}\begin{matrix}\dfrac{3}{4}-2x=\dfrac{1}{4}\\\dfrac{3}{4}-2x=\dfrac{-1}{4}\end{matrix}\right.\)     
=> \(\left\{{}\begin{matrix}2x=\dfrac{3}{4}-\dfrac{1}{4}\\2x=\dfrac{3}{4}+\dfrac{1}{4}\end{matrix}\right.\)
=> \(\left\{{}\begin{matrix}2x=\dfrac{1}{2}\\2x=1\end{matrix}\right.\)
=> \(\left\{{}\begin{matrix}x=\dfrac{1}{4}\\x=\dfrac{1}{2}\end{matrix}\right.\)
     Vậy x \(\in\left\{\dfrac{1}{4};\dfrac{1}{2}\right\}\)