(x+1)(x-1)+18=3(x+3)

Solution for (x+1)(x-1)+18=3(x+3) equation:

Simplifying
(x + 1)(x + -1) + 18 = 3(x + 3)

Reorder the terms:
(1 + x)(x + -1) + 18 = 3(x + 3)

Reorder the terms:
(1 + x)(-1 + x) + 18 = 3(x + 3)

Multiply (1 + x) * (-1 + x)
(1(-1 + x) + x(-1 + x)) + 18 = 3(x + 3)
((-1 * 1 + x * 1) + x(-1 + x)) + 18 = 3(x + 3)
((-1 + 1x) + x(-1 + x)) + 18 = 3(x + 3)
(-1 + 1x + (-1 * x + x * x)) + 18 = 3(x + 3)
(-1 + 1x + (-1x + x2)) + 18 = 3(x + 3)

Combine like terms: 1x + -1x = 0
(-1 + 0 + x2) + 18 = 3(x + 3)
(-1 + x2) + 18 = 3(x + 3)

Reorder the terms:
-1 + 18 + x2 = 3(x + 3)

Combine like terms: -1 + 18 = 17
17 + x2 = 3(x + 3)

Reorder the terms:
17 + x2 = 3(3 + x)
17 + x2 = (3 * 3 + x * 3)
17 + x2 = (9 + 3x)

Solving
17 + x2 = 9 + 3x

Solving for variable 'x'.

Reorder the terms:
17 + -9 + -3x + x2 = 9 + 3x + -9 + -3x

Combine like terms: 17 + -9 = 8
8 + -3x + x2 = 9 + 3x + -9 + -3x

Reorder the terms:
8 + -3x + x2 = 9 + -9 + 3x + -3x

Combine like terms: 9 + -9 = 0
8 + -3x + x2 = 0 + 3x + -3x
8 + -3x + x2 = 3x + -3x

Combine like terms: 3x + -3x = 0
8 + -3x + x2 = 0

Begin completing the square.

Move the constant term to the right:

Add '-8' to each side of the equation.
8 + -3x + -8 + x2 = 0 + -8

Reorder the terms:
8 + -8 + -3x + x2 = 0 + -8

Combine like terms: 8 + -8 = 0
0 + -3x + x2 = 0 + -8
-3x + x2 = 0 + -8

Combine like terms: 0 + -8 = -8
-3x + x2 = -8

The x term is -3x.  Take half its coefficient (-1.5).
Square it (2.25) and add it to both sides.

Add '2.25' to each side of the equation.
-3x + 2.25 + x2 = -8 + 2.25

Reorder the terms:
2.25 + -3x + x2 = -8 + 2.25

Combine like terms: -8 + 2.25 = -5.75
2.25 + -3x + x2 = -5.75

Factor a perfect square on the left side:
(x + -1.5)(x + -1.5) = -5.75

Can't calculate square root of the right side.

The solution to this equation could not be determined.