3x^2-9=72

Solution for 3x^2-9=72 equation:

Simplifying
3x2 + -9 = 72

Reorder the terms:
-9 + 3x2 = 72

Solving
-9 + 3x2 = 72

Solving for variable 'x'.

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

Add '9' to each side of the equation.
-9 + 9 + 3x2 = 72 + 9

Combine like terms: -9 + 9 = 0
0 + 3x2 = 72 + 9
3x2 = 72 + 9

Combine like terms: 72 + 9 = 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}