Respuesta :

x^2 = 81...take the square root of both sides, eliminating the ^2
x = (+-) sqrt 81
x = (+-) 9

answers are : -9 and 9
If 81 equals to x² (so the unknown number is 81 when x is squared), the to find x you do the square root of 81.

x = ±√81

x = ±9

Answers are either C and E