3x*x-72=13

Solution for 3x*x-72=13 equation:

Simplifying
3x * x + -72 = 13

Multiply x * x
3x2 + -72 = 13

Reorder the terms:
-72 + 3x2 = 13

Solving
-72 + 3x2 = 13

Solving for variable 'x'.

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

Add '72' to each side of the equation.
-72 + 72 + 3x2 = 13 + 72

Combine like terms: -72 + 72 = 0
0 + 3x2 = 13 + 72
3x2 = 13 + 72

Combine like terms: 13 + 72 = 85
3x2 = 85

Divide each side by '3'.
x2 = 28.33333333

Simplifying
x2 = 28.33333333

Take the square root of each side:
x = {-5.322906474, 5.322906474}