[tex]~~x^2+10x+25 = 27\\\\\implies x^2+2\cdot 5 x +5^2 = 27\\\\\implies (x+5)^2 = 27\\\\\implies x +5 = \pm\sqrt{27}\\\\\implies x = -5 \pm\sqrt{3\times 9}\\\\\implies x = -5 \pm3\sqrt 3\\\\\text{Hence,}~~ x = -5 + 3 \sqrt 3 ,~~~ x =-5-3\sqrt3[/tex]