Answer:
x = 9
Explanation:
The area of a square is A = x².
"x" is for side.
The opposite of the exponent of 2 is square root.
Use the area formula.
A = x² We know the area is 81.
81 = x² Now you can square root both sides.
√81 = √x² √ and ² cancel out and leaves "x" alone.
9 = x