Question

Thực hiện pháp tính :

25.(\(\dfrac{-1}{5}\)) + \(\dfrac{1}{5}\) - 2 . (\(\dfrac{-1}{2}\))\(^2\) - \(\sqrt{\dfrac{1}{4}}\)

Tìm x : 

6 - | \(\dfrac{1}{2}\) - x | = \(\dfrac{2}{5}\)

 

 

Answer 1

\(a,=-5+\dfrac{1}{5}-2\cdot\dfrac{1}{4}-\dfrac{1}{2}=-5-1+\dfrac{1}{5}=-\dfrac{29}{5}\\ b,\Rightarrow\left|\dfrac{1}{2}-x\right|=\dfrac{28}{5}\Rightarrow\left[{}\begin{matrix}\dfrac{1}{2}-x=\dfrac{28}{5}\\x-\dfrac{1}{2}=\dfrac{28}{5}\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=-\dfrac{51}{10}\\x=\dfrac{61}{10}\end{matrix}\right.\)