\begin{equation}4x^{2}=4\end{equation}

\begin{equation}25x^{2}+10x+1=0\end{equation}

\begin{equation}x^{2}+25=0\end{equation}

\begin{equation}x^{2}+8x+16=0\end{equation}

\begin{equation}x^{2}+14x+149=0\end{equation}

\begin{equation}x^{2}+9x+18=0\end{equation}

\begin{equation}50x^{2}+15x+1=0\end{equation}

\begin{equation}50x^{2}+90x+40=0\end{equation}

\begin{equation}x^{2}+14x+47=0\end{equation}

\begin{equation}4x^{2}+4x-7=0\end{equation}

\begin{equation}81x^{2}+36x-6=0\end{equation}

\begin{equation}81x^{2}+18x+5=0\end{equation}

\begin{equation}16x^{2}+56x+52=0\end{equation}