9.9=x*x

Solution for 9.9=x*x equation:

Simplifying
9.9 = x * x

Multiply x * x
9.9 = x2

Solving
9.9 = x2

Solving for variable 'x'.

Move all terms containing x to the left, all other terms to the right.

Add '-1x2' to each side of the equation.
9.9 + -1x2 = x2 + -1x2

Combine like terms: x2 + -1x2 = 0
9.9 + -1x2 = 0

Add '-9.9' to each side of the equation.
9.9 + -9.9 + -1x2 = 0 + -9.9

Combine like terms: 9.9 + -9.9 = 0.0
0.0 + -1x2 = 0 + -9.9
-1x2 = 0 + -9.9

Combine like terms: 0 + -9.9 = -9.9
-1x2 = -9.9

Divide each side by '-1'.
x2 = 9.9

Simplifying
x2 = 9.9

Take the square root of each side:
x = {-3.146426545, 3.146426545}