Question

Which equation results from taking the square root of both sides (x-9)^2=81

Answer 1

$(x-9)^2=81\\\\\sqrt{(x-9)^2}=\sqrt{81}\\\\|x-9|=9\iff x-9=9\ \vee\ x-9=-9\ \ \ |+9\\\\x=19\ \vee\ x=0$

Answer 2

$\bf (x-9)^2=81\implies \sqrt{(x-9)^2}=\sqrt{81}\implies x-9=\pm \sqrt{81} \\\\\\ x-9=\pm 9\implies x=\pm 9+9$