2(x^2-8)=84

Solution for 2(x^2-8)=84 equation:

Simplifying
2(x2 + -8) = 84

Reorder the terms:
2(-8 + x2) = 84
(-8 * 2 + x2 * 2) = 84
(-16 + 2x2) = 84

Solving
-16 + 2x2 = 84

Solving for variable 'x'.

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

Add '16' to each side of the equation.
-16 + 16 + 2x2 = 84 + 16

Combine like terms: -16 + 16 = 0
0 + 2x2 = 84 + 16
2x2 = 84 + 16

Combine like terms: 84 + 16 = 100
2x2 = 100

Divide each side by '2'.
x2 = 50

Simplifying
x2 = 50

Take the square root of each side:
x = {-7.071067812, 7.071067812}