x=0.3x^2+13.9

Solution for x=0.3x^2+13.9 equation:

Simplifying
x = 0.3x2 + 13.9

Reorder the terms:
x = 13.9 + 0.3x2

Solving
x = 13.9 + 0.3x2

Solving for variable 'x'.

Reorder the terms:
-13.9 + x + -0.3x2 = 13.9 + 0.3x2 + -13.9 + -0.3x2

Reorder the terms:
-13.9 + x + -0.3x2 = 13.9 + -13.9 + 0.3x2 + -0.3x2

Combine like terms: 13.9 + -13.9 = 0.0
-13.9 + x + -0.3x2 = 0.0 + 0.3x2 + -0.3x2
-13.9 + x + -0.3x2 = 0.3x2 + -0.3x2

Combine like terms: 0.3x2 + -0.3x2 = 0.0
-13.9 + x + -0.3x2 = 0.0

Begin completing the square.  Divide all terms by
-0.3 the coefficient of the squared term: 

Divide each side by '-0.3'.
46.33333333 + -3.333333333x + x2 = 0

Move the constant term to the right:

Add '-46.33333333' to each side of the equation.
46.33333333 + -3.333333333x + -46.33333333 + x2 = 0 + -46.33333333

Reorder the terms:
46.33333333 + -46.33333333 + -3.333333333x + x2 = 0 + -46.33333333

Combine like terms: 46.33333333 + -46.33333333 = 0.00000000
0.00000000 + -3.333333333x + x2 = 0 + -46.33333333
-3.333333333x + x2 = 0 + -46.33333333

Combine like terms: 0 + -46.33333333 = -46.33333333
-3.333333333x + x2 = -46.33333333

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.
-3.333333333x + 0.25 + x2 = -46.33333333 + 0.25

Reorder the terms:
0.25 + -3.333333333x + x2 = -46.33333333 + 0.25

Combine like terms: -46.33333333 + 0.25 = -46.08333333
0.25 + -3.333333333x + x2 = -46.08333333

Factor a perfect square on the left side:
(x + 0.5)(x + 0.5) = -46.08333333

Can't calculate square root of the right side.

The solution to this equation could not be determined.