x^2+20x+400=0

Solution for x^2+20x+400=0 equation:

Simplifying
x2 + 20x + 400 = 0

Reorder the terms:
400 + 20x + x2 = 0

Solving
400 + 20x + 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 + 20x + -400 + x2 = 0 + -400

Reorder the terms:
400 + -400 + 20x + x2 = 0 + -400

Combine like terms: 400 + -400 = 0
0 + 20x + x2 = 0 + -400
20x + x2 = 0 + -400

Combine like terms: 0 + -400 = -400
20x + x2 = -400

The x term is 20x.  Take half its coefficient (10).
Square it (100) and add it to both sides.

Add '100' to each side of the equation.
20x + 100 + x2 = -400 + 100

Reorder the terms:
100 + 20x + x2 = -400 + 100

Combine like terms: -400 + 100 = -300
100 + 20x + x2 = -300

Factor a perfect square on the left side:
(x + 10)(x + 10) = -300

Can't calculate square root of the right side.

The solution to this equation could not be determined.