`(x-1/2)^2 +(2x-1)^2=0`
\(\Rightarrow\left(x^2-x+\dfrac{1}{4}\right)+\left(4x^2-4x+1\right)=0\\ \Rightarrow x^2-x+\dfrac{1}{4}+4x^2-4x+1=0\\ \Rightarrow5x^2-5x+\dfrac{5}{4}=0\\ \Rightarrow\dfrac{5}{4}\left(4x^2-4x+1\right)=0\\ \Rightarrow\dfrac{5}{4}\left(2x-1\right)^2=0\\ \Rightarrow\left(2x-1\right)^2=0\\ \Rightarrow2x-1=0\\ \Rightarrow2x=0+1\\ \Rightarrow2x=1\\ \Rightarrow x=\dfrac{1}{2}\)