x^2+x+400=0

Solution for x^2+x+400=0 equation:

Simplifying
x2 + x + 400 = 0

Reorder the terms:
400 + x + x2 = 0

Solving
400 + x + x2 = 0

Solving for variable 'x'.

Begin completing the square.

Move the constant term to the right:

Add '-400' to each side of the equation.
400 + x + -400 + x2 = 0 + -400

Reorder the terms:
400 + -400 + x + x2 = 0 + -400

Combine like terms: 400 + -400 = 0
0 + x + x2 = 0 + -400
x + x2 = 0 + -400

Combine like terms: 0 + -400 = -400
x + x2 = -400

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.
x + 0.25 + x2 = -400 + 0.25

Reorder the terms:
0.25 + x + x2 = -400 + 0.25

Combine like terms: -400 + 0.25 = -399.75
0.25 + x + x2 = -399.75

Factor a perfect square on the left side:
(x + 0.5)(x + 0.5) = -399.75

Can't calculate square root of the right side.

The solution to this equation could not be determined.