x-18=3x^2

Solution for x-18=3x^2 equation:

Simplifying
x + -18 = 3x2

Reorder the terms:
-18 + x = 3x2

Solving
-18 + x = 3x2

Solving for variable 'x'.

Combine like terms: 3x2 + -3x2 = 0
-18 + x + -3x2 = 0

Begin completing the square.  Divide all terms by
-3 the coefficient of the squared term: 

Divide each side by '-3'.
6 + -0.3333333333x + x2 = 0

Move the constant term to the right:

Add '-6' to each side of the equation.
6 + -0.3333333333x + -6 + x2 = 0 + -6

Reorder the terms:
6 + -6 + -0.3333333333x + x2 = 0 + -6

Combine like terms: 6 + -6 = 0
0 + -0.3333333333x + x2 = 0 + -6
-0.3333333333x + x2 = 0 + -6

Combine like terms: 0 + -6 = -6
-0.3333333333x + x2 = -6

The x term is x.  Take half its coefficient (0.5).
Square it (0.25) and add it to both sides.

Add '0.25' to each side of the equation.
-0.3333333333x + 0.25 + x2 = -6 + 0.25

Reorder the terms:
0.25 + -0.3333333333x + x2 = -6 + 0.25

Combine like terms: -6 + 0.25 = -5.75
0.25 + -0.3333333333x + x2 = -5.75

Factor a perfect square on the left side:
(x + 0.5)(x + 0.5) = -5.75

Can't calculate square root of the right side.

The solution to this equation could not be determined.