(4+x^2)-(49-x^2)-(36-x^2)=0

Solution for (4+x^2)-(49-x^2)-(36-x^2)=0 equation:

Simplifying
(4 + x2) + -1(49 + -1x2) + -1(36 + -1x2) = 0

Remove parenthesis around (4 + x2)
4 + x2 + -1(49 + -1x2) + -1(36 + -1x2) = 0
4 + x2 + (49 * -1 + -1x2 * -1) + -1(36 + -1x2) = 0
4 + x2 + (-49 + 1x2) + -1(36 + -1x2) = 0
4 + x2 + -49 + 1x2 + (36 * -1 + -1x2 * -1) = 0
4 + x2 + -49 + 1x2 + (-36 + 1x2) = 0

Reorder the terms:
4 + -49 + -36 + x2 + 1x2 + 1x2 = 0

Combine like terms: 4 + -49 = -45
-45 + -36 + x2 + 1x2 + 1x2 = 0

Combine like terms: -45 + -36 = -81
-81 + x2 + 1x2 + 1x2 = 0

Combine like terms: x2 + 1x2 = 2x2
-81 + 2x2 + 1x2 = 0

Combine like terms: 2x2 + 1x2 = 3x2
-81 + 3x2 = 0

Solving
-81 + 3x2 = 0

Solving for variable 'x'.

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

Add '81' to each side of the equation.
-81 + 81 + 3x2 = 0 + 81

Combine like terms: -81 + 81 = 0
0 + 3x2 = 0 + 81
3x2 = 0 + 81

Combine like terms: 0 + 81 = 81
3x2 = 81

Divide each side by '3'.
x2 = 27

Simplifying
x2 = 27

Take the square root of each side:
x = {-5.196152423, 5.196152423}