(x+1)(x-2)+x=0

Solution for (x+1)(x-2)+x=0 equation:

Simplifying
(x + 1)(x + -2) + x = 0

Reorder the terms:
(1 + x)(x + -2) + x = 0

Reorder the terms:
(1 + x)(-2 + x) + x = 0

Multiply (1 + x) * (-2 + x)
(1(-2 + x) + x(-2 + x)) + x = 0
((-2 * 1 + x * 1) + x(-2 + x)) + x = 0
((-2 + 1x) + x(-2 + x)) + x = 0
(-2 + 1x + (-2 * x + x * x)) + x = 0
(-2 + 1x + (-2x + x2)) + x = 0

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

Reorder the terms:
-2 + -1x + x + x2 = 0

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

Solving
-2 + x2 = 0

Solving for variable 'x'.

Move all terms containing x to the left, all other terms to the right.

Add '2' to each side of the equation.
-2 + 2 + x2 = 0 + 2

Combine like terms: -2 + 2 = 0
0 + x2 = 0 + 2
x2 = 0 + 2

Combine like terms: 0 + 2 = 2
x2 = 2

Simplifying
x2 = 2

Take the square root of each side:
x = {-1.414213562, 1.414213562}