Question

Which of the numbers listed below are solutions to the equation? Check all that apply. x2 = 81 A. 18 B. 40.5 C. -9 D. 162 E. 9 F. 6561

Answer 1

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

Answer 2

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

answers are : -9 and 9