Question

Tìm x , biết :

a,\(\left(x-\dfrac{1}{2}\right)^5=\dfrac{1}{243}\)

b,\(\left|2x-1\right|-x=1\)

c, \(\left|\dfrac{3}{5}-\dfrac{1}{2}x\right|>\dfrac{2}{5}\)

Answer 1

a: =>x-1/2=1/3

=>x=5/6

b: =>|2x-1|=x+1

\(\Leftrightarrow\left\{{}\begin{matrix}x>=-1\\\left(2x-1-x-1\right)\left(2x-1+x+1\right)=0\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x>=-1\\\left(x-2\right)\left(3x\right)=0\end{matrix}\right.\)

hay \(x\in\left\{2;0\right\}\)

c: \(\Leftrightarrow\left[{}\begin{matrix}\dfrac{1}{2}x-\dfrac{3}{5}>\dfrac{2}{5}\\\dfrac{1}{2}x-\dfrac{3}{5}< -\dfrac{2}{5}\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}\dfrac{1}{2}x>1\\\dfrac{1}{2}x< \dfrac{1}{5}\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x>2\\x< \dfrac{2}{5}\end{matrix}\right.\)