Find all solutions, real or imaginary, using the method of your choice. Round solutions to three decimal places when needed
$\displaystyle -{5}{\left({x}-{2}\right)}^{{2}}-{20}={0}$



Tip: Write your answers as a list, with your answers separated by (a) comma(s). For example, if you get $\displaystyle {4}$ and $\displaystyle -\frac{{2}}{{3}}$ as your answers, then enter 4,-2/3 in the box.