Question

Answer 1

\(a,ĐK:x\ne0;x\ne\pm\dfrac{1}{2}\\ A=\dfrac{2x+1-3-4x+2}{\left(2x-1\right)\left(2x+1\right)}\cdot\dfrac{2x+1}{x}=\dfrac{-2x}{x\left(2x-1\right)}=\dfrac{2}{1-2x}\\ b,x=-2\Leftrightarrow A=\dfrac{2}{1+4}=\dfrac{2}{5}\\ c,A=4\Leftrightarrow\dfrac{2}{1-2x}=4\Leftrightarrow1-2x=\dfrac{1}{2}\\ \Leftrightarrow2x=\dfrac{1}{2}\Leftrightarrow x=\dfrac{1}{4}\left(tm\right)\\ d,A=1\Leftrightarrow2=1-2x\Leftrightarrow2x=-1\Leftrightarrow x=-\dfrac{1}{2}\left(ktm\right)\\ \Leftrightarrow x\in\varnothing\)