x(x+1)=(x+x+1)-11

Solution for x(x+1)=(x+x+1)-11 equation:

Simplifying
x(x + 1) = (x + x + 1) + -11

Reorder the terms:
x(1 + x) = (x + x + 1) + -11
(1 * x + x * x) = (x + x + 1) + -11
(1x + x2) = (x + x + 1) + -11

Reorder the terms:
1x + x2 = (1 + x + x) + -11

Combine like terms: x + x = 2x
1x + x2 = (1 + 2x) + -11

Remove parenthesis around (1 + 2x)
1x + x2 = 1 + 2x + -11

Reorder the terms:
1x + x2 = 1 + -11 + 2x

Combine like terms: 1 + -11 = -10
1x + x2 = -10 + 2x

Solving
1x + x2 = -10 + 2x

Solving for variable 'x'.

Reorder the terms:
10 + 1x + -2x + x2 = -10 + 2x + 10 + -2x

Combine like terms: 1x + -2x = -1x
10 + -1x + x2 = -10 + 2x + 10 + -2x

Reorder the terms:
10 + -1x + x2 = -10 + 10 + 2x + -2x

Combine like terms: -10 + 10 = 0
10 + -1x + x2 = 0 + 2x + -2x
10 + -1x + x2 = 2x + -2x

Combine like terms: 2x + -2x = 0
10 + -1x + x2 = 0

Begin completing the square.

Move the constant term to the right:

Add '-10' to each side of the equation.
10 + -1x + -10 + x2 = 0 + -10

Reorder the terms:
10 + -10 + -1x + x2 = 0 + -10

Combine like terms: 10 + -10 = 0
0 + -1x + x2 = 0 + -10
-1x + x2 = 0 + -10

Combine like terms: 0 + -10 = -10
-1x + x2 = -10

The x term is -1x.  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.
-1x + 0.25 + x2 = -10 + 0.25

Reorder the terms:
0.25 + -1x + x2 = -10 + 0.25

Combine like terms: -10 + 0.25 = -9.75
0.25 + -1x + x2 = -9.75

Factor a perfect square on the left side:
(x + -0.5)(x + -0.5) = -9.75

Can't calculate square root of the right side.

The solution to this equation could not be determined.