\(1,\\ A=\left|2x-\dfrac{1}{3}\right|-1\dfrac{3}{4}\ge-1\dfrac{3}{4}\\ A_{min}=-1\dfrac{3}{4}\Leftrightarrow2x=\dfrac{1}{3}\Leftrightarrow x=\dfrac{1}{6}\\ 2,\\ A=2,25-\dfrac{1}{4}\left|1+2x\right|\le2,25\\ A_{max}=2,25\Leftrightarrow1+2x=0\Leftrightarrow x=-\dfrac{1}{2}\)