-0.3=0.2-2b^2

Solution for -0.3=0.2-2b^2 equation:

Simplifying
-0.3 = 0.2 + -2b2

Solving
-0.3 = 0.2 + -2b2

Solving for variable 'b'.

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

Add '2b2' to each side of the equation.
-0.3 + 2b2 = 0.2 + -2b2 + 2b2

Combine like terms: -2b2 + 2b2 = 0
-0.3 + 2b2 = 0.2 + 0
-0.3 + 2b2 = 0.2

Add '0.3' to each side of the equation.
-0.3 + 0.3 + 2b2 = 0.2 + 0.3

Combine like terms: -0.3 + 0.3 = 0.0
0.0 + 2b2 = 0.2 + 0.3
2b2 = 0.2 + 0.3

Combine like terms: 0.2 + 0.3 = 0.5
2b2 = 0.5

Divide each side by '2'.
b2 = 0.25

Simplifying
b2 = 0.25

Take the square root of each side:
b = {-0.5, 0.5}