3x^2-[-x^2-(8x^2-5)]=

Solution for 3x^2-[-x^2-(8x^2-5)]= equation:

Simplifying
3x2 + -1[-1x2 + -1(8x2 + -5)] = 0

Reorder the terms:
3x2 + -1[-1x2 + -1(-5 + 8x2)] = 0
3x2 + -1[-1x2 + (-5 * -1 + 8x2 * -1)] = 0
3x2 + -1[-1x2 + (5 + -8x2)] = 0

Reorder the terms:
3x2 + -1[5 + -1x2 + -8x2] = 0

Combine like terms: -1x2 + -8x2 = -9x2
3x2 + -1[5 + -9x2] = 0
3x2 + [5 * -1 + -9x2 * -1] = 0
3x2 + [-5 + 9x2] = 0

Reorder the terms:
-5 + 3x2 + 9x2 = 0

Combine like terms: 3x2 + 9x2 = 12x2
-5 + 12x2 = 0

Solving
-5 + 12x2 = 0

Solving for variable 'x'.

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

Add '5' to each side of the equation.
-5 + 5 + 12x2 = 0 + 5

Combine like terms: -5 + 5 = 0
0 + 12x2 = 0 + 5
12x2 = 0 + 5

Combine like terms: 0 + 5 = 5
12x2 = 5

Divide each side by '12'.
x2 = 0.4166666667

Simplifying
x2 = 0.4166666667

Take the square root of each side:
x = {-0.645497224, 0.645497224}