3x^2-4x+21=3

Solution for 3x^2-4x+21=3 equation:

Simplifying
3x2 + -4x + 21 = 3

Reorder the terms:
21 + -4x + 3x2 = 3

Solving
21 + -4x + 3x2 = 3

Solving for variable 'x'.

Reorder the terms:
21 + -3 + -4x + 3x2 = 3 + -3

Combine like terms: 21 + -3 = 18
18 + -4x + 3x2 = 3 + -3

Combine like terms: 3 + -3 = 0
18 + -4x + 3x2 = 0

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

Divide each side by '3'.
6 + -1.333333333x + x2 = 0

Move the constant term to the right:

Add '-6' to each side of the equation.
6 + -1.333333333x + -6 + x2 = 0 + -6

Reorder the terms:
6 + -6 + -1.333333333x + x2 = 0 + -6

Combine like terms: 6 + -6 = 0
0 + -1.333333333x + x2 = 0 + -6
-1.333333333x + x2 = 0 + -6

Combine like terms: 0 + -6 = -6
-1.333333333x + x2 = -6

The x term is -1.333333333x.  Take half its coefficient (-0.6666666665).
Square it (0.4444444442) and add it to both sides.

Add '0.4444444442' to each side of the equation.
-1.333333333x + 0.4444444442 + x2 = -6 + 0.4444444442

Reorder the terms:
0.4444444442 + -1.333333333x + x2 = -6 + 0.4444444442

Combine like terms: -6 + 0.4444444442 = -5.5555555558
0.4444444442 + -1.333333333x + x2 = -5.5555555558

Factor a perfect square on the left side:
(x + -0.6666666665)(x + -0.6666666665) = -5.5555555558

Can't calculate square root of the right side.

The solution to this equation could not be determined.