.20=k^2

Solution for .20=k^2 equation:

Simplifying
0.20 = k2

Solving
0.20 = k2

Solving for variable 'k'.

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

Add '-1k2' to each side of the equation.
0.20 + -1k2 = k2 + -1k2

Combine like terms: k2 + -1k2 = 0
0.20 + -1k2 = 0

Add '-0.20' to each side of the equation.
0.20 + -0.20 + -1k2 = 0 + -0.20

Combine like terms: 0.20 + -0.20 = 0.00
0.00 + -1k2 = 0 + -0.20
-1k2 = 0 + -0.20

Combine like terms: 0 + -0.20 = -0.2
-1k2 = -0.2

Divide each side by '-1'.
k2 = 0.2

Simplifying
k2 = 0.2

Take the square root of each side:
k = {-0.447213596, 0.447213596}