a/ Ta có :
\(\left|2x-\dfrac{1}{5}\right|\ge0\)
\(\Leftrightarrow\left|2x-\dfrac{1}{5}\right|+98\ge98\)
\(\Leftrightarrow A\ge98\)
Dấu "=" xảy ra khi :
\(\left|2x-\dfrac{1}{5}\right|=0\Leftrightarrow x=\dfrac{1}{10}\)
Vậy ...
b/ \(\left|x+1,5\right|\ge0\)
\(\Leftrightarrow\left|x+1,5\right|-4,5\ge-4,5\)
\(\Leftrightarrow B\ge-4,5\)
Dấu "=" xảy ra khi :
\(\left|x+1,5\right|=0\Leftrightarrow x=-1,5\)
Vậy...
c/ \(\left|x+1,1\right|\ge0\)
\(\Leftrightarrow1,5-\left|x+1,1\right|\le1,5\)
\(\Leftrightarrow C\le1,5\)
Dấu "=" xảy ra khi :
\(\left|x+1,1\right|=0\Leftrightarrow x=-1,1\)
Vậy ...
d/ \(\left|2x-4\right|\ge0\)
\(\Leftrightarrow3-\left|2x-4\right|\le3\)
\(\Leftrightarrow D\le3\)
Dấu "=" xảy ra khi :
\(\left|2x-4\right|=0\Leftrightarrow x=2\)
Vậy..
