.25(1156-3*x^2)=0

Solution for .25(1156-3*x^2)=0 equation:

Simplifying
0.25(1156 + -3x2) = 0
(1156 * 0.25 + -3x2 * 0.25) = 0
(289 + -0.75x2) = 0

Solving
289 + -0.75x2 = 0

Solving for variable 'x'.

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

Add '-289' to each side of the equation.
289 + -289 + -0.75x2 = 0 + -289

Combine like terms: 289 + -289 = 0
0 + -0.75x2 = 0 + -289
-0.75x2 = 0 + -289

Combine like terms: 0 + -289 = -289
-0.75x2 = -289

Divide each side by '-0.75'.
x2 = 385.3333333

Simplifying
x2 = 385.3333333

Take the square root of each side:
x = {-19.629909152, 19.629909152}