\(D=-3-\left|2x+4\right|\)
\(\left|2x+4\right|\ge0\forall x\)
\(D=-3-\left|2x+4\right|\le3\)
Dấu "=" xảy ra khi:
\(\left|2x+4\right|=0\Rightarrow x=-2\)
\(A=3\left|1-2x\right|-5\)
\(\left|1-2x\right|\ge0\Rightarrow3\left|1-2x\right|\ge0\forall x\)
\(A=3\left|1-2x\right|-5\ge-5\)
Dấu "=" xảy ra khi:
\(3\left|1-2x\right|=0\Rightarrow2x=1\Rightarrow x=\dfrac{1}{2}\)