-r^2-2r-6=0

Solution for -r^2-2r-6=0 equation:

Simplifying
-1r2 + -2r + -6 = 0

Reorder the terms:
-6 + -2r + -1r2 = 0

Solving
-6 + -2r + -1r2 = 0

Solving for variable 'r'.

Factor out the Greatest Common Factor (GCF), '-1'.
-1(6 + 2r + r2) = 0

Ignore the factor -1.
Subproblem 1
Set the factor '(6 + 2r + r2)' equal to zero and attempt to solve:

Simplifying
6 + 2r + r2 = 0

Solving
6 + 2r + r2 = 0

Begin completing the square.

Move the constant term to the right:

Add '-6' to each side of the equation.
6 + 2r + -6 + r2 = 0 + -6

Reorder the terms:
6 + -6 + 2r + r2 = 0 + -6

Combine like terms: 6 + -6 = 0
0 + 2r + r2 = 0 + -6
2r + r2 = 0 + -6

Combine like terms: 0 + -6 = -6
2r + r2 = -6

The r term is 2r.  Take half its coefficient (1).
Square it (1) and add it to both sides.

Add '1' to each side of the equation.
2r + 1 + r2 = -6 + 1

Reorder the terms:
1 + 2r + r2 = -6 + 1

Combine like terms: -6 + 1 = -5
1 + 2r + r2 = -5

Factor a perfect square on the left side:
(r + 1)(r + 1) = -5

Can't calculate square root of the right side.

The solution to this equation could not be determined.

This subproblem is being ignored because a solution could not be determined.

The solution to this equation could not be determined.