[tex]x^2-6x+13=0\\\\\implies x^2-6x =-13\\\\\implies x^2 -2\cdot 3 \cdot x+3^2 -3^2 =-13\\\\\implies (x-3)^2 -9 = -13\\\\\implies (x-3)^2 = -13 +9 = -4\\\\ \implies x-3 =\pm\sqrt{-4} \\\\\implies x -3 = \pm2i\\\\\implies x = \pm 2i +3\\\\\text{Hence,}~ x = 3 + 2i, ~~ x = 3-2i[/tex]
