$$20.2 x ^ { 2 } + a x - a ^ { 2 } = 0$$
$a=-\frac{\sqrt{2045x^{2}}}{10}+\frac{x}{2}$
$a=\frac{\sqrt{2045x^{2}}}{10}+\frac{x}{2}$
$x=\frac{\sqrt{2045a^{2}}-5a}{202}$
$x=\frac{-\sqrt{2045a^{2}}-5a}{202}$
$a=\frac{\left(5-\sqrt{2045}\right)x}{10}$
$a=\frac{\left(\sqrt{2045}+5\right)x}{10}$
$x=\frac{\left(\sqrt{2045}-5\right)a}{202}$
$x=-\frac{\left(\sqrt{2045}+5\right)a}{202}$
